Analog Devices AD9444 Service Manual

14-Bit, 80 MSPS, A/D Converter

FEATURES

80 MSPS guaranteed sampling rate
100 dB two-tone SFDR with 69.3 MHz and 70.3 MHz

73.1 dB SNR with 70 MHz input
97 dBc SFDR with 70 MHz input
Excellent linearity

DNL = ±0.4 LSB typical
INL = ±0.6 LSB typical

1.2 W power dissipation

3.3 V and 5 V supply operation

2.0 V p-p differential full-scale input
LVDS outputs (ANSI-644 compatible)
Data format select
Output clock available

APPLICATIONS

Multicarrier, multimode cellular receivers
Antenna array positioning
Power amplifier linearization
Broadband wireless
Radar, infared imaging
Communications instrumentation

GENERAL DESCRIPTION

The AD9444 is a 14-bit monolithic, sampling analog-to-digital
converter (ADC) with an on-chip, track-and-hold circuit and is
optimized for power, small size, and ease of use. The product
operates at up to an 80 MSPS conversion rate and is optimized
for multicarrier, multimode receivers, such as those found in
cellular infrastructure equipment.

The ADC requires 3.3 V and 5.0 V power supplies and a low
voltage differential input clock for full performance operation.
No external reference or driver components are required for
many applications. Data outputs are LVDS-compatible (ANSI-

644) or CMOS-compatible and include the means to reduce
the overall current needed for short trace distances.

AD9444

FUNCTIONAL BLOCK DIAGRAM

AGND DRGND DRVDD

AVDD1 AVDD2

2

28

2

DFS
DCS MODE
OUTPUT MODE
OR

D13–D0

DCO

AD9444

VIN+
VIN–

CLK+
CLK–

BUFFER

CLOCK

AND TIMING

MANAGEMENT

T/H

VREF

PIPELINE

ADC

REF

Figure 1.

14

CMOS

OR

LVDS

OUTPUT

STAGING

REFBSENSE REFT

Optional features allow users to implement various selectable
operating conditions, including data format select and output
data mode.

The AD9444 is available in a 100-lead surface-mount plastic
package (100-lead TQFP/EP) specified over the industrial
temperature range (−40°C to +85°C).

PRODUCT HIGHLIGHTS

1. High performance: Outstanding SFDR performance for mul-

ticarrier, multimode 3G and 4G cellular base station
receivers.

2. Ease of use: On-chip reference and track-and-hold. An

output clock simplifies data capture.

3. Packaged in a Pb-free, 100-lead TQFP/EP.

4. Clock DCS maintains overall ADC performance over a wide

range of clock pulse widths.

5. OR (out-of-range) outputs indicate when the signal is beyond

the selected input range.

05089-001

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

www.analog.com

AD9444

TABLE OF CONTENTS

DC Specifications ............................................................................. 3

Clock Input Considerations...................................................... 22

AC Specifications.............................................................................. 4

Digital Specifications........................................................................ 5

Switching Specifications .................................................................. 6

Explanation of Test Levels........................................................... 7

Absolute Maximum Ratings............................................................ 8

ESD Caution.................................................................................. 8

Definitions of Specifications........................................................... 9

Pin Configurations and Function Descriptions .........................10

Equivalent Circuits......................................................................... 14

Typical Performance Characteristics........................................... 15

Theory of Operation ...................................................................... 20

Analog Input and Reference Overview ...................................20

REVISION HISTORY

10/04—Revision 0: Initial Version

Power Considerations................................................................ 23

Digital Outputs ........................................................................... 23

Timing ......................................................................................... 23

Operational Mode Selection ..................................................... 23

Evaluation Board ........................................................................ 24

LVDS Evaluation Board Schematics........................................ 25

LVDS Mode Evaluation Board Bill of Materials (BOM) ...... 30

CMOS Evaluation Board Schematics...................................... 32

CMOS Mode Evaluation Board Bill of Materials (BOM)..... 37

Outline Dimensions....................................................................... 39

Ordering Guide .......................................................................... 39

Rev. 0 | Page 2 of 40

AD9444

DC SPECIFICATIONS

AVDD1 = 3.3 V, AVDD2 = 5.0 V, DRVDD = 3.3 V, LVDS mode, sample rate = 80 MSPS, 2 V p-p differential input, internal trimmed
reference (1.0 V mode), A

Table 1.

Parameter Temp Test Level

RESOLUTION Full VI 14 Bits
ACCURACY

No Missing Codes Full VI Guaranteed
Offset Error Full VI 6 ±0.3 6 mV
Gain Error

1

Differential Nonlinearity (DNL)

Integral Nonlinearity (INL)2 25°C I −1.3 ±0.6 +1.3 LSB
Full VI −1.7 +1.7 LSB
TEMPERATURE DRIFT

Offset Error Full V 12 µV/°C

Gain Error Full V 0.002 %FS/°C
VOLTAGE REFERENCE

Output Voltage1 Full VI 0.87 1.0 1.13 V

Load Regulation @ 1.0 mA Full V ±2 mV

Reference Input Current (External 1.0 V Reference) Full VI 80 125 µA
INPUT REFERRED NOISE 25°C V 1.0 LSB rms
ANALOG INPUT

Input Span Full V 2 V p-p

Input Common-Mode Voltage Full V 3.5 V

Input Resistance

3

Input Capacitance3 Full V 2.5 pF
POWER SUPPLIES

Supply Voltage

AVDD1 Full IV 3.14 3.3 3.46 V
AVDD2 Full IV 4.75 5.0 5.25 V
DRVDD—LVDS Outputs Full IV 3.0 3.6 V
DRVDD—CMOS Outputs Full IV 3.0 3.3 3.6 V

Supply Current

AVDD1 Full VI 217 240 mA
AVDD22 Full VI 71 80 mA
IDRVDD2—LVDS Outputs Full VI 55 62 mA
IDRVDD2—CMOS Outputs Full V 12 mA

PSRR

Offset Full V 1 mV/V
Gain Full V 0.2 %/V

POWER CONSUMPTION

DC Input—LVDS Outputs Full VI 1.21 1.4 W

DC Input—CMOS Outputs Full V 1.07 W

Sine Wave Input2—LVDS Outputs Full VI 1.25 W

Sine Wave Input2—CMOS Outputs Full V 1.11 W

1

The internal voltage reference is trimmed at final test to minimize the gain error of the AD9444.

2

Measured at the maximum clock rate, fIN = 15 MHz, full-scale sine wave, with a 100 Ω differential termination on each pair of output bits for LVDS output mode and

approximately 5 pF loading on each output bit for CMOS output mode.

3

Input capacitance or resistance refers to the effective impedance between one differential input pin and AGND. Refer to for the equivalent analog input

structure.

= −0.5 dBFS, DCS on, unless other wise note d.

IN

Full VI −3.0 ±0.4 +3.0 % FSR

2

Full VI −0.8 ±0.4 +0.8 LSB

Full V 1 kΩ

AD9444BSVZ-80

Min Typ Max

Figure 6

Unit

Rev. 0 | Page 3 of 40

AD9444

AC SPECIFICATIONS

AVDD1 = 3.3 V, AVDD2 = 5.0 V, DRVDD = 3.3 V, LVDS mode, sample rate = 80 MSPS, 2 V p-p differential input, internal trimmed
reference (1.0 V mode), A

Table 2.

Parameter Temp Test Level

SIGNAL-TO-NOISE-RATIO (SNR)

fIN = 10 MHz 25°C IV 73.0 74.0 dB

Full IV 72.7 dB

fIN = 35 MHz 25°C I 72.4 73.7 dB
Full IV 72.3 dB
fIN = 70 MHz 25°C IV 72.3 73.1 dB

Full IV 72.0 dB

fIN = 100 MHz 25°C V 72.3 dB

SIGNAL-TO-NOISE-AND DISTORTION (SINAD)

fIN = 10 MHz 25°C IV 73.0 74.0 dB

Full IV 72.7 dB

fIN = 35 MHz 25°C I 72.4 73.7 dB
Full IV 72.2 dB
fIN = 70 MHz 25°C IV 72.2 73.1 dB

Full IV 72.0 dB

fIN = 100 MHz 25°C V 72.3 dB

EFFECTIVE NUMBER OF BITS (ENOB)

fIN = 10 MHz 25°C V 12.1 Bits
fIN = 35 MHz 25°C V 12.0 Bits
fIN = 70 MHz 25°C V 11.9 Bits
fIN = 100 MHz 25°C V 11.8 Bits

SPURIOUS-FREE DYNAMIC RANGE (SFDR)

fIN = 10 MHz 25°C IV 91 97 dBc

Full IV 87 dBc

fIN = 35 MHz 25°C I 91 97 dBc
Full IV 87 dBc
fIN = 70 MHz 25°C IV 90 97 dBc

Full IV 87 dBc

fIN = 100 MHz 25°C V 96 dBc

WORST HARMONIC, SECOND OR THIRD

fIN = 10 MHz 25°C IV −97 −91 dBc

Full IV −87 dBc

fIN = 35 MHz 25°C I −97 −91 dBc
Full IV −87 dBc
fIN = 70 MHz 25°C IV −97 −90 dBc

Full IV −87 dBc

fIN = 100 MHz 25°C V −96 dBc

WORST SPUR EXCLUDING SECOND OR HARMONICS

fIN = 10 MHz 25°C IV −102 −93 dBc

Full IV −93 dBc

fIN = 35 MHz 25°C I −103 −93 dBc
Full IV −93 dBc
fIN = 70 MHz 25°C IV −102 −93 dBc

Full IV −93 dBc

fIN = 100 MHz 25°C V −99 dBc

TWO-TONE SFDR

fIN = 10.8 MHz @ −7 dBFS, 9.8 MHz @ −7 dBFS 25°C V −102 dBFS
fIN = 70.3 MHz @ −7 dBFS, 69.3 MHz @ −7 dBFS 25°C V −100 dBFS

ANALOG BANDWIDTH Full V 650 MHz

= −0.5 dBFS, DCS on, unless other wise note d.

IN

AD9444BSVZ-80

Min Typ Max

Unit

Rev. 0 | Page 4 of 40

AD9444

DIGITAL SPECIFICATIONS

AVDD1 = 3.3 V, AVDD2 = 5.0 V, DRVDD = 3.3 V, R

Table 3.

Parameter Temp Test Level

CMOS LOGIC INPUTS (DFS, DCS MODE, OUTPUT MODE)

High Level Input Voltage Full IV 2.0 V

Low Level Input Voltage Full IV 0.8 V

High Level Input Current Full VI +200 µA

Low Level Input Current Full VI −10 +10 µA

Input Capacitance Full V 2 pF
DIGITAL OUTPUT BITS—CMOS Mode (D0 to D13, OTR)

DRVDD = 3.3 V

High Level Output Voltage Full IV 3.25 V
Low Level Output Voltage Full IV 0.2 V

DIGITAL OUTPUT BITS LVDS Mode (D0 to D13, OTR)

VOD Differential Output Voltage

2

VOS Output Offset Voltage Full VI 1.125 1.375 V
CLOCK INPUTS (CLK+, CLK−)

Differential Input Voltage Full IV 0.2 V

Common-Mode Voltage Full VI 1.3 1.5 1.6 V

Differential Input Resistance Full V 8 10 12 kΩ

Differential Input Capacitance Full V 4 pF

1

Output voltage levels measured with 5 pF load on each output.

2

LVDS R

= 100 Ω.

TERM

= 3.74 kΩ, unless otherwise noted.

LVD SB IA S

1

Full VI 247 545 mV

AD9444BSVZ-80

Min Typ Max

Unit

Rev. 0 | Page 5 of 40

AD9444

SWITCHING SPECIFICATIONS

AVDD1 = 3.3 V, AVDD2 = 5.0 V, DRVDD = 3.3 V, unless otherwise noted.

Table 4.

AD9444BSVZ-80

Parameter Temp Test Level

Min Typ Max

CLOCK INPUT PARAMETERS

Maximum Conversion Rate Full VI 80 MSPS
Minimum Conversion Rate Full V 10 MSPS
CLK Period Full V 12.5 ns
CLK Pulse Width High1 (t
CLK Pulse Width Low1 (t

) Full V 4 ns

CLKH

) Full V 4 ns

CLKL

DATA OUTPUT PARAMETERS

Output Propagation Delay—CMOS (tPD)2 (DX, DCO+) Full IV 3 5.25 8 ns
Output Propagation Delay—LVDS (tPD)3 (DX+, DCO+) Full VI 3 5 7.5 ns
Pipeline Delay (Latency) Full V 12 Cycles
Aperture Delay (tA) Full V ns
Aperture Uncertainty (Jitter, tJ) Full V 0.2 ps rms

1

With duty cycle stabilizer (DCS) enabled.

2

Output propagation delay is measured from clock 50% transition to data 50% transition, with 5 pF load.

3

LVDS R

= 100 Ω. Measured from the 50% point of the rising edge of CLK+ to the 50% point of the data transition.

TERM

Unit

A

CLK+

CLK–

DATA OUT

DCO+

DCO–

N–1

IN

t

CLKH

t

CLKL

t

CPD

N

N+1

1/f

S

t

PD

N–12

12 CLOCK CYCLES

N–11

N

N+1

05089-002

Figure 2. LVDS Mode Timing Diagram

Rev. 0 | Page 6 of 40

AD9444

N

N+1

t

CLKL

t

PD

N+2

12 CYCLES

VIN

CLK–

CLK+

N–1

t

CLKH

DX

DCO+

DCO–

N-12 N-11 N-1 N

t

DCOPD

Figure 3. CMOS Timing Diagram

EXPLANATION OF TEST LEVELS

Test Level Definitions

I 100% production tested.
II 100% production tested at 25°C and sample tested at specified temperatures.
III Sample tested only.
IV Parameter is guaranteed by design and characterization testing.
V Parameter is a typical value only.
VI 100% production tested at 25°C and guaranteed by design and characterization for industrial temperature range.

05089-003

Rev. 0 | Page 7 of 40

AD9444

ABSOLUTE MAXIMUM RATINGS

Table 5.

With

Parameter
ELECTRICAL

AVDD1 AGND −0.3 +4 V
AVDD2 AGND −0.3 +6 V
DRVDD DGND −0.3 +4 V
AGND DGND −0.3 +0.3 V
AVDD1 DRVDD −4 +4 V
AVDD2 DRVDD −4 +6 V
AVDD2 AVDD1 −4 +6 V
D0 to D13 DGND –0.3 DRVDD + 0.3 V
CLK, MODE AGND –0.3 AVDD1 + 0.3 V
VIN+, VIN− AGND –0.3 AVDD2 + 0.3 V
VREF AGND –0.3 AVDD1 + 0.3 V
SENSE AGND –0.3 AVDD1 + 0.3 V
REFT, REFB AGND –0.3 AVDD1 + 0.3 V

ENVIRONMENTAL

Storage Temperature –65 +125 °C
Operating Temperature Range –40 +85 °C
Lead Temperature Range

(Soldering 10 sec)

Junction Temperature 150 °C

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

Respect to

Min Max Unit

300 °C

Thermal Resistance

The heat sink of the AD9444 package must be soldered to
ground.

Table 6.

Package Type θ

100-Lead TQFP/EP 19.8 8.3 2 °C/W

JA

θ

JB

θ

JC

Unit

Typical θ

= 19.8°C/W (heat-sink soldered) for multilayer

JA

board in still air.

Typical θ

= 8.3°C/W (heat-sink soldered) for multilayer board

JB

in still air.

Typical θ

= 2°C/W (junction to exposed heat sink) represents

JC

the thermal resistance through heat-sink path.

Airflow increases heat dissipation effectively reducing θ

. Also,

JA

more metal directly in contact with the package leads, from
metal traces, through holes, ground, and power planes, reduces

. It is required that the exposed heat sink be soldered to

the θ

JA

the ground plane.

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the
human body and test equipment and can discharge without detection. Although this product features proprie­tary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic
discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of
functionality.

Rev. 0 | Page 8 of 40

AD9444

DEFINITIONS OF SPECIFICATIONS

Analog Bandwidth (Full Power Bandwidth)

The analog input frequency at which the spectral power of the
fundamental frequency (as determined by the FFT analysis) is
reduced by 3 dB.

Minimum Conversion Rate

The clock rate at which the SNR of the lowest analog signal
frequency drops by no more than 3 dB below the guaranteed
limit.

Aperture Delay (t

)

A

The delay between the 50% point of the rising edge of the clock
and the instant at which the analog input is sampled.

Aperture Uncertainty (Jitter, t

)

J

The sample-to-sample variation in aperture delay.

Clock Pulse Width and Duty Cycle
Pulse width high is the minimum amount of time that the
clock pulse should be left in the Logic 1 state to achieve rated
performance. Pulse width low is the minimum time the clock
pulse should be left in the low state. At a given clock rate, these
specifications define an acceptable clock duty cycle.

Differential Nonlinearity (DNL, No Missing Codes)

An ideal ADC exhibits code transitions that are exactly 1 LSB
apart. DNL is the deviation from this ideal value. Guaranteed no
missing codes to 14-bit resolution indicates that all 16384 codes
must be present over all operating ranges.

Effective Number of Bits (ENOB)

The effective number of bits for a sine wave input at a given
input frequency can be calculated directly from its measured
SINAD using the following formula

()

SINAD

=

ENOB

1.76−

6.02

Gain Error

The first code transition should occur at an analog value ½ LSB
above negative full scale. The last transition should occur at an
analog value 1 ½ LSB below the positive full scale. Gain error is
the deviation of the actual difference between first and last code
transitions and the ideal difference between first and last code
transitions.

Offset Error

The major carry transition should occur for an analog value
½ LSB below VIN+ = VIN−. Offset error is defined as the
deviation of the actual transition from that point.

Out-of-Range Recovery Time

The time it takes for the ADC to reacquire the analog input
after a transition from 10% above positive full scale to 10%
above negative full scale, or from 10% below negative full scale
to 10% below positive full scale.

Output Propagation Delay (tPD)

The delay between the clock rising edge and the time when all
bits are within valid logic levels.

Power-Supply Rejection Ratio

The change in full scale from the value with the supply at the
minimum limit to the value with the supply at its maximum limit.

Signal-to-Noise and Distortion (SINAD)

The ratio of the rms input signal amplitude to the rms value of
the sum of all other spectral components below the Nyquist
frequency, including harmonics but excluding dc.

Signal-to-Noise Ratio (SNR)

The ratio of the rms input signal amplitude to the rms value of
the sum of all other spectral components below the Nyquist
frequency, excluding the first six harmonics and dc.

Spurious-Free Dynamic Range (SFDR)

The ratio of the rms signal amplitude to the rms value of the
peak spurious spectral component. The peak spurious compo­nent may or may not be a harmonic. May be reported in dBc
(i.e., degrades as signal level is lowered) or dBFS (always related
back to converter full scale).

Integral Nonlinearity (INL)

The deviation of each individual code from a line drawn from
negative full scale through positive full scale. The point used as
negative full scale occurs ½ LSB before the first code transition.
Positive full scale is defined as a level 1 ½ LSBs beyond the last
code transition. The deviation is measured from the middle of
each particular code to the true straight line.

Maximum Conversion Rate

The clock rate at which parametric testing is performed.

Rev. 0 | Page 9 of 40

Temperature Drift

The temperature drift for offset error and gain error specifies
the maximum change from the initial (25°C) value to the value
at T

MIN

or T

MAX

.

Total Harmonic Distortion (THD)

The ratio of the rms input signal amplitude to the rms value of
the sum of the first six harmonic components.

Two -Ton e SFDR

The ratio of the rms value of either input tone to the rms value
of the peak spurious component. The peak spurious component
may or may not be an IMD product.

AD9444

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

DCS MODE

AGND

AVDD1

AGND

AGND

AVDD1

AVDD1

AVDD1

AVDD1

AVDD1

AVDD1

AVDD1

AGND

AVDD1

AGND

OR+

OR–

AVDD1

DNC
DNC
DNC

OUTPUT MODE

DFS

LVDSBIAS

AVDD1
AVDD1
SENSE

VREF

AGND

REFT
REFB

AGND
AVDD1
AVDD1

AVDD1
AVDD2

AGND

VIN+
VIN–

AGND
AVDD1

AVDD1

99989796959493

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2
3
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5
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8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

929190

89

88

AD9444

TOP VIEW

(Not to Scale)

8786858483

DRVDD

DRGND
82

D13+ (MSB)

D13–79D12+78D12–77D11+76D11–

81

80

75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51

DRVDD
DRGND
D10+

D10–
D9+

D9–
D8+
D8–

DRGND
D7+

D7–
DCO+
DCO–
DRVDD
DRGND
D6+
D6–
D5+

D5–
D4+

D4–
DRVDD
DRGND

D3+
D3–

2627282930

AVDD1

AVDD1

DNC = DO NOT CONNECT

AVDD2

AVDD2

AVDD2

31

AVDD2

32

C1

AGND

33

343536

AVDD1

AVDD1

CLK+

37

39

40

38

414243

4445464748

D1–

D0+

CLK–

AVDD1

AVDD2

AVDD2

AVDD1

AVDD1

D1+

(LSB) D0–

DRVDD

49

D2–

DRGND

50

D2+

05089-004

Figure 4. 100-Lead TQFP/EP Pin Configuration in LVDS Mode

Rev. 0 | Page 10 of 40

AD9444

Table 7. Pin Function Descriptions—100-Lead TQFP/EP in LVDS Mode

Pin No. Mnemonic Description

1, 8 to 9,
16 to 18,
24 to 27,
34 to 35, 38,
41 to 42, 87,
89 to 95, 98

2 to 4 DNC

5

6 DFS

7 LVDSBIAS

10 SENSE

11 VREF

12, 15, 20,
23, 32, 86,
88, 96 to 97,
99, Exposed
Heat Sink

13 REFT

14 REFB

19, 28 to 31,
39 to 40

21 VIN+ Analog Input—True.
22 VIN− Analog Input—Complement.
33 C1

36 CLK+ Clock Input—True.
37 CLK− Clock Input—Complement.
43 D0− (LSB)

AVDD1 3.3 V (±5%) Analog Supply.

Do Not Connect. These pins
should float.

OUTPUT
MODE

AGND

AVDD2 5.0 V Analog Supply (±5%).

CMOS Compatible Output Logic
Mode Control Pin. OUTPUT MODE
= 0 for CMOS mode, and OUTPUT
MODE = 1 (AVDD1) for LVDS
outputs.

Data Format Select Pin. CMOS
control pin that determines the
format of the output data. DFS =
high (AVDD1) for twos comple­ment, DFS = low (ground) for
offset binary format.

Set Pin for LVDS Output Current.
Place 3.7 kΩ resistor terminated to
DRGND.

Reference Mode Selection.
Connect to AGND for internal 1 V
reference, and connect to AVDD2
for external reference.

1.0 V Reference I/O—Function
Dependent on SENSE. Decouple
to ground with 0.1 µF and 10 µF
capacitors.

Analog Ground. The exposed
heat sink on the bottom of the
package must be connected to
AGND.

Differential Reference Output.
Decoupled to ground with 0.1 µF
capacitor and to REFB (Pin 14) with

0.1 µF and 10 µF capacitors.
Differential Reference Output.

Decoupled to ground with a 0.1 µF
capacitor and to REFT (Pin 13) with

0.1 µF and 10 µF capacitors.

Internal Bypass Node. Connect a

0.1 µF capacitor from this pin
to AGND.

D0 Complement Output Bit
(LVDS Levels).

Pin No. Mnemonic Description

44 D0+ D0 True Output Bit.
45 D1− D1 Complement Output Bit.
46 D1+ D1 True Output Bit.
47, 54, 62,

75, 83
48, 53, 61,

67, 74, 82
49 D2− D2 Complement Output Bit.
50 D2+ D2 True Output Bit.
51 D3− D3 Complement Output Bit.
52 D3+ D3 True Output Bit.
55 D4− D4 Complement Output Bit.
56 D4+ D4 True Output Bit.
57 D5− D5 Complement Output Bit.
58 D5+ D5 True Output Bit.
59 D6− D6 Complement Output Bit.
60 D6+ D6 True Output Bit.
63 DCO− Data Clock Output—Complement.
64 DCO+ Data Clock Output—True.
65 D7− D7 Complement Output Bit.
66 D7+ D7 True Output Bit.
68 D8− D8 Complement Output Bit.
69 D8+ D8 True Output Bit.
70 D9− D9 Complement Output Bit.
71 D9+ D9 True Output Bit.
72 D10− D10 Complement Output Bit.
73 D10+ D10 True Output Bit.
76 D11− D11 Complement Output Bit.
77 D11+ D11 True Output Bit.
78 D12− D12 Complement Output Bit.
79 D12+ D12 True Output Bit.
80 D13− D13 Complement Output.
81 D13+ (MSB) D13 True Output Bit.
84 OR−

85 OR+ Out-of-Range True Output Bit.
100 DCS MODE

DRVDD

DRGND Digital Ground.

3.3 V Digital Output Supply
(3.0 V to 3.6 V).

Out-of-Range Complement
Output Bit.

Clock Duty Cycle Stabilizer (DCS)
Control Pin, CMOS-Compatible.
DCS = low (AGND) to enable DCS
(recommended). DCS = high
(AVDD1) to disable DCS.

Rev. 0 | Page 11 of 40

AD9444

AVDD1

DNC
DNC
DNC

OUTPUT MODE

DFS

DNC

AVDD1
AVDD1
SENSE

VREF

AGND

REFT

REFB

AGND
AVDD1
AVDD1
AVDD1
AVDD2

AGND

VIN+
VIN–

AGND
AVDD1
AVDD1

DCS MODE

AGND

AVDD1

AGND

AGND

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23
24
25

AVDD1

AVDD1

AVDD1

AVDD1

AVDD1

929190

AVDD1

AVDD1

AGND

89

88

AD9444

TOP VIEW

(Not to Scale)

AVDD1

AGNDORD13 (MSB)

8786858483

DRVDD

DRGND

D12

81

82

D11
80

D10D9D8
797877

D7
76

75

DRVDD

74

DRGND

73

D6

72

D5

71

D4

70

D3

69

D2

68

D1

67

DRGND

66

D0 (LSB)

65

DNC

64

DCO+

63

DCO–

62

DRVDD

61

DRGND

60

DNC

59

DNC

58

DNC

57

DNC

56

DNC
DNC

55
54

DRVDD

53

DRGND

52

DNC

51

DNC

2627282930

AVDD1

AVDD1

DNC = DO NOT CONNECT

Figure 5. 100-Lead TQFP/EP Pin Configuration in CMOS Mode

AVDD2

AVDD2

AVDD2

31

AVDD2

32

AGND

33
C1

343536

AVDD1

AVDD1

CLK+

37

CLK–

38

AVDD1

39

AVDD2

40

AVDD2

414243

AVDD1

AVDD1

4445464748

DNC

DNC

DNC

DNC

DRVDD

49

DNC

DRGND

50

DNC

05089-005

Rev. 0 | Page 12 of 40

AD9444

Table 8. Pin Function Descriptions—100-Lead TQFP/EP in CMOS Mode

Pin No. Mnemonic Description

1, 8 to 9, 16 to 18,
24 to 27, 34 to 35,
38, 41 to 42, 87,
89 to 95, 98

2 to 4, 7,
43 to 46, 49 to 52,
55 to 60, 65

5

6 DFS

10 SENSE

11 VREF

12, 15, 20, 23,
32, 86, 88, 96 to
97, 99, Exposed
Heat Sink

13 REFT

14 REFB

19, 28 to 31,
39 to 40

21 VIN+ Analog Input—True.
22 VIN− Analog Input—Complement.

AVDD1 3.3 V (±5%) Analog Supply.

DNC

OUTPUT
MODE

AGND

AVDD2 5.0 V Analog Supply (±5%).

Do Not Connect. These
pins should float.

CMOS Compatible Output
Logic Mode Control Pin.
OUTPUT MODE = 0 for CMOS
mode, and OUTPUT MODE =
1 (AVDD1) for LVDS outputs.

Data Format Select Pin.
CMOS control pin that de­termines the format of the
output data. DFS = high
(AVDD1) for twos comple­ment, DFS = low (ground) for
offset binary format.

Reference Mode Selection.
Connect to AGND for internal
1 V reference, and connect to
AVDD2 for external reference.

1.0 V Reference I/O—
Function Dependent on
SENSE. Decouple to ground
with 0.1 µF and 10 µF
capacitors.

Analog Ground. The exposed
heat sink on the bottom of
the package must be
connected to AGND.

Differential Reference Out­put. Decoupled to ground
with 0.1 µF capacitor and to
REFB (Pin 14) with 0.1 µF and
10 µF capacitors.

Differential Reference Out­put. Decoupled to ground
with a 0.1 µF capacitor and to
REFT (Pin 13) with 0.1 µF and
10 µF capacitors.

Pin No. Mnemonic Description

33 C1

36 CLK+ Clock Input—True.
37 CLK− Clock Input—Complement.
47, 54, 62,

75, 83
48, 53, 61,

67, 74, 82
63 DCO−

64 DCO+

66 D0 (LSB)

68 D1 D1 Output Bit.
69 D2 D2 Output Bit.
70 D3 D3 Output Bit.
71 D4 D4 Output Bit.
72 D5 D5 Output Bit.
73 D6 D6 Output Bit.
76 D7 D7 Output Bit.
77 D8 D8 Output Bit.
78 D9 D9 Output Bit.
79 D10 D10 Output Bit.
80 D11 D11 Output Bit.
81 D12 D12 Output Bit.
84 D13 (MSB) D13 Output Bit.
85 OR Out-of-Range Output.
100 DCS MODE

DRVDD

DRGND Digital Ground.

Internal Bypass Node.
Connect a 0.1 µF capacitor
from this pin to AGND.

3.3 V Digital Output
Supply (2.5V to 3.6 V).

Data Clock Output—
Complement (CMOS Levels).

Data Clock Output—
True.

D0 Output Bit (LSB)
(CMOS Levels).

Clock Duty Cycle Stabilizer
(DCS) Control Pin, CMOS­Compatible. DCS = low
(AGND) to enable DCS
(recommended). DCS =
high (AVDD1) to disable DCS.

Rev. 0 | Page 13 of 40

AD9444

EQUIVALENT CIRCUITS

AVDD2

VIN+

AVDD2

2.5pF

3.5V

X1

DRVDD

1k

Ω

DX

SHA

1k

AVDD2

VIN–

2.5pF

Ω

Figure 6. Equivalent Analog Input Circuit

DRVDD DRVDD

I

LVDSOUT

K

1.2V

LVDSBIAS

3.74k

Ω

Figure 7. Equivalent LVDS BIAS Circuit

DRVDD

V

DX– DX+

V

V

V

05089-008

Figure 8. Equivalent LVDS Digital Output Circuit

05089-006

05089-007

05089-009

Figure 9. Equivalent CMOS Digital Output Circuit

VDD

DCS MODE,

OUTPUT MODE,

DFS

30k

Ω

05089-010

Figure 10. Equivalent Digital Input Circuit,

DFS, DCS MODE, OUTPUT MODE

AVDD2

Ω

CLK+

10k

12k

150

Ω

Ω

12k

150

Ω

Ω

10k

Ω

CLK–

05089-011

Figure 11. Equivalent Sample Clock Input Circuit

Rev. 0 | Page 14 of 40

AD9444

TYPICAL PERFORMANCE CHARACTERISTICS

AVDD1 = 3.3 V, AVDD2 = 5.0 V, DRVDD = 3.3 V, sample rate = 80 MSPS, LVDS mode, DCS enabled, TA = 25°C, 2 V p-p differential
input, AIN = −0.5 dBFS, internal trimmed reference (nominal VREF = 1.0 V), unless otherwise noted.

–20

–40

0

80MSPS

10.1MHz @ –0.5dBFS
SNR: 73.9dB
ENOB: 12.0BITS
SFDR: 97dBc

–20

–40

0

80MSPS

100.3MHz @ –0.5dBFS
SNR: 72.3dB
ENOB: 11.8BITS
SFDR: 96dBc

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

Figure 12. 64K Point Single-Tone FFT/80 MSPS/10.1 MHz

0

80MSPS

30.3MHz @ –0.5dBFS
SNR: 74.0dB

–20

ENOB: 12.1BITS
SFDR: 95dBc

–40

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

Figure 13. 64K Point Single-Tone FFT/80 MSPS/30.3 MHz

05089-012

05089-013

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

Figure 15. 64K Point Single-Tone FFT/80 MSPS/100 MHz

0

80MSPS
125MHz @ –0.5dBFS
SNR: 71.2dB

–20

ENOB: 11.6BITS
SFDR: 91dBc

–40

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

Figure 16. 64K Point Single-Tone FFT/80 MSPS/125 MHz

05089-015

05089-016

0

–20

–40

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

80MSPS

70.3MHz @ –0.5dBFS
SNR: 73.3dB
ENOB: 11.9BITS
SFDR: 100dBc

Figure 14. 64K Point Single-Tone FFT/80 MSPS/70 MHz

05089-014

Rev. 0 | Page 15 of 40

0

–20

–40

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

80MSPS
151MHz @ –0.5dBFS
SNR: 71.1dB
ENOB: 11.5BITS
SFDR: 87dBc

Figure 17. 64K Point Single-Tone FFT/80 MSPS/151 MHz

05089-017

AD9444

75

74

73

72

71

70

(dB)

69

68

67

66
65

0 20 40 60 80 100 120 140 160 180 200

Figure 18. SNR vs. Analog Input Frequency, 80 MSPS/LVDS Mode

SNR dB @ –40°C

SNR dB @ +25°C

SNR dB @ +85°C

ANALOG INPUT FREQUENCY (MHz)

05089-018

75

74

73

72

SNR dB @ +25°C

71

70

(dB)

69

68

67

66

65

0 20 40 60 80 100 120 140 160 180 200

SNR dB @ –40°C

SNR dB @ +85°C

ANALOG INPUT FREQUENCY (MHz)

Figure 21. SNR vs. Analog Input Frequency, 80 MSPS/CMOS Mode

05089-021

105

100

(dB)

SFDR dBc @ +85°C

95

90

85

80

75

70

0 20 40 60 80 100 120 140 160 180 200

SFDR dBc @ –40°C

ANALOG INPUT FREQUENCY (MHz)

SFDR dBc @ +25°C

Figure 19. SFDR vs. Analog Input Frequency, 80 MSPS/LVDS Mode

120
110
100

90
80
70

(dB)

60
50
40
30
20
10

–100 –90 –80 –70 –60 –50 –40 –30 –20 –10 0

THIRD –dBFS

SFDR –dBFS

ANALOG INPUT AMPLITUDE (dBc)

SECOND –dBFS

SECOND –dBc

THIRD –dBc

SFDR –dBFS

Figure 20. Single-Tone SFDR/Second/Third vs.

Analog Input Level, 80 MSPS, A

= 30.3 MHz

IN

05089-019

05089-020

105

SFDR dBc @ +85°C

100

95

90

SFDR dBc @ –40°C

(dB)

85

80

75

70

0 20 40 60 80 100 120 140 160 180 200

ANALOG INPUT FREQUENCY (MHz)

SFDR dBc @ +25°C

Figure 22. SFDR vs. Analog Input Frequency, 80 MSPS/CMOS Mode

120
110
100

90
80
70

(dB)

60
50
40
30
20
10

–100 –90 –80 –70 –60 –50 –40 –30 –20 –10 0

SFDR –dBFS

THIRD –dBc

ANALOG INPUT AMPLITUDE (dBc)

SECOND –dBFS

SECOND –dBc

THIRD –dBFS

SFDR –dBFS

Figure 23. Single-Tone SFDR/Second/Third vs.

Analog Input Level 80 MSPS, A

= 70.30 MHz

IN

05089-022

05089-023

Rev. 0 | Page 16 of 40

AD9444

0

–20

–40

–60

–80

AMPLITUDE (dBFS)

–100

–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

SFDR: 102dBFS

Figure 24. 32K Point Two-Tone FFT 80 MSPS/9.8 MHz/10.8 MHz

05089-024

0
–10
–20
–30

SFDR (dBc)

–40
–50

IMD (dBFS)

–100
–110
–120

–60
–70
–80
–90

WORST THIRD-ORDER IMD (dBc)

–110 –100 –90 –80 –70 –60 –50 –40 –30 –20 –10 0

90dBFS REFERENCE LINE

SFDR (dBFS)

WORST THIRD-ORDER IMD (dBFS)

ANALOG INPUT LEVEL (dBFS)

Figure 27. Two-Tone SFDR vs. Analog Input Level, A

= 9.8 MHz/10.8 MHz

IN

05089-027

0
–10
–20
–30
–40
–50
–60
–70
–80

AMPLITUDE (dBFS)

–90

–100
–110
–120

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

SFDR: –100dBFS

Figure 25. 32K Point Two-Tone FFT 80 MSPS/69.3 MHz/70.3 MHz

100

95

90

85

SFDR (dB)

80

05089-025

0
–10
–20
–30

SFDR (dBc)

–40
–50
–60

WORST THIRD-ORDER IMD (dBc)

–70
–80

SFDR AND IMD3 (dB)

–90

–100
–110
–120

–110 –100 –90 –80 –70 –60 –50 –40 –30 –20 –10 0

90dBFS REFERENCE LINE

SFDR (dBFS)

WORST THIRD-ORDER IMD (dBFS)

ANALOG INPUT LEVEL (dBFS)

Figure 28. Two-Tone SFDR vs. Analog Input Level, A

100

95

90

85

SFDR (dB)

80

= 69.3 MHz/70.3 MHz

IN

05089-028

75

70

20 30 40 50 60 70 80 90 100 110

Figure 26. SFDR vs. Sample Rate, V

SAMPLE RATE (MSPS)

= 10.3 MHz @ −0.5 dBFS

IN

05089-026

Rev. 0 | Page 17 of 40

75

70

10 20 30 40 50 60 70 80 90 100 110

Figure 29. SFDR vs. Sample Rate, V

SAMPLE RATE (MSPS)

= 70.3 MHz @ −0.5 dBFS

IN

05089-029

AD9444

0
–10
–20
–30
–40
–50
–60
–70
–80

AMPLITUDE (dBFS)

–90

–100
–110
–120
–130

0 7.68 15.36 23.04 30.72

FREQUENCY (MHz)

Figure 30. 64K FFT, 61.44 MSPS, 4 @ WCDMA, IF = 46.08 MHz

0
–10
–20
–30
–40
–50
–60
–70
–80

AMPLITUDE (dBFS)

–90

–100
–110
–120
–130

0 5 10 15 20 25 30 35 40

FREQUENCY (MHz)

Figure 31. NPR, 80 MSPS/18 MHz Notch

61.44MSPS
TOTAL INPUT SIGNAL
POWER: –30dBFS

NPR: 63.1dB

05089-030

05089–031

12000

10000

8000

6000

FREQUENCY

4000

2000

0

8179 8180 8181 8182 8183 8184 8185 8186 8187

B

IN

Figure 33. Ground Input Histogram

80 MSPS, VIN+ = VIN−, 32K Samples

250

230

210

190

170

150

130

CURRENT (mA)

110

90

70

50

DRVDD (3.3V)

20 30 40 50 60 70 80 90 100 110 120 130

Figure 34. I

AVDD1 (3.3V)

AVDD2 (5.0V)

SAMPLE RATE (MSPS)

vs. Sample Rate, AIN = 10.3 MHz @ −0.5 dBFS

SUPPLY

05089-033

05089-034

105

SFDR - DCS ON (dBFS)

100

95

90

dB

85

80

75

SNR - DCS ON (dB)

70

20 30 40 50 60 70 80

SFDR - DCS OFF (dBFS)

SNR - DCS OFF (dB)

CLOCK DUTY CYCLE (%)

Figure 32. Single-Tone SNR/SFDR vs. Clock Duty Cycle,

= 80 MSPS, 10.3 MHz @ −0.5 dBFS

F

SAMPLE

05089-032

Rev. 0 | Page 18 of 40

100

95

90

85

80

(dB)

75

70

65

60

2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9

SFDR (dBc)

SNR (dB)

V

COMMON-MODE (V)

IN

Figure 35. Single-Tone SNR/SFDR vs.

Common-Mode Voltage 80 MSPS/10.3 MHz

V

IN

05089-035

AD9444

0.961

0.960

0.959

0.958

0.957

0.956

0.955

0.954

REFERENCE VOLTAGE (V)

0.953

0.952

0.951
–20 0 20 40 60 80

–40

TEMPERATURE (°C)

Figure 36. VREF vs. Temperature

05089-036

GAIN (%FS)

0.2

0.1

–0.1

–0.2

–0.3

–0.4

–0.5

0

–20 0 20 40 60 80

–40

TEMPERATURE (°C)

Figure 38. Gain vs. Temperature

05089-038

1.00

0.75

0.50

0.25

0

–0.25

DNL ERROR (LSB)

–0.50

–0.75

–1.00

0 2048 4096 6144 8192 10240 12288 14336 16384

OUTPUT CODE

Figure 37. DNL Error vs. Output Code, 80 MSPS, A

= 15 MHz

IN

05089-037

1.00

0.75

0.50

0.25

0

–0.25

INL ERROR (LSB)

–0.50

–0.75

–1.00

0 2048 4096 6144 8192 10240 12288 14336 16384

OUTPUT CODE

Figure 39. INL Error vs. Output Code, 80 MSPS, A

= 15 MHz

IN

05089-039

Rev. 0 | Page 19 of 40

AD9444

THEORY OF OPERATION

The AD9444 architecture is optimized for high speed and ease
of use. The analog inputs drive an integrated, high bandwidth,
track-and-hold circuit that samples the signal prior to quantiza­tion by the 14-bit pipeline ADC core. The device includes an
on-board reference and input logic that accepts TTL, CMOS, or
LVPECL levels. The digital output logic levels are user selectable
as standard 3 V CMOS or LVDS (ANSI-644 compatible) via the
OUTPUT MODE pin.

ANALOG INPUT AND REFERENCE OVERVIEW

A stable and accurate 0.5 V voltage reference is built into the
AD9444. The input range can be adjusted by varying the refer­ence voltage applied to the AD9444, using either the internal
reference or an externally applied reference voltage. The input
span of the ADC tracks reference voltage changes linearly. The
various reference modes are described in the next few sections.

Internal Reference Connection

A comparator within the AD9444 detects the potential at the
SENSE pin and configures the reference into four possible
states, which are summarized in Table 9. If SENSE is grounded,
the reference amplifier switch is connected to the internal resis­tor divider (see Figure 40), setting VREF to ~1 V. Connecting
the SENSE pin to VREF switches the reference amplifier output
to the SENSE pin, completing the loop and providing a ~0.5 V
reference output. If a resistor divider is connected, as shown in
Figure 41, the switch again sets to the SENSE pin. This puts the
reference amplifier in a noninverting mode with the VREF
output defined as

R2

VREF 10.5

⎛
⎜

⎝

In all reference configurations, REFT and REFB drive the A/D
conversion core and establish its input span. The input range of
the ADC always equals twice the voltage at the reference pin for
either an internal or an external reference.

⎞

+×=

⎟

R1

⎠

Internal Reference Trim

The internal reference voltage is trimmed during the produc­tion test to adjust the gain (analog input voltage range) of the
AD9444. Therefore, there is little advantage to the user supply­ing an external voltage reference to the AD9444. The gain trim
is performed with the AD9444’s input range set to 2 V p-p
nominal (SENSE connected to AGND). Because of this trim,
and because the 2 V p-p analog input range provides maximum
ac performance, there is little benefit to using analog input
ranges < 2 V p-p. Users are cautioned that the differential
nonlinearity of the ADC varies with the reference voltage.
Configurations that use < 2 V p-p may exhibit missing codes
and, therefore, degraded noise and distortion performance.

VIN+

10µF+0.1µF

10µF+0.1µF

VIN–

ADC

CORE

VREF

SELECT

LOGIC

SENSE

0.5V

AD9444

Figure 40. Internal Reference Configuration

VIN+
VIN–

VREF

R2
SENSE

SELECT

LOGIC

ADC

CORE

REFT

0.1µF

0.1µF 10µF

REFB

0.1µF

REFT

0.1µF

0.1µF 10µF

REFB

0.1µF

+

+

05089-043

Rev. 0 | Page 20 of 40

R1

Figure 41. Programmable Reference Configuration

0.5V

AD9444

05089-042

AD9444

Table 9. Reference Configuration Summary

Selected Mode SENSE Voltage Resulting VREF (V) Resulting Differential Span (V p-p)

External Reference AVDD N/A 2 × External Reference
Internal Fixed Reference VREF 0.5 1.0
Programmable Reference 0.2 V to VREF

R2

⎛
⎜

⎝

⎞

(See Figure 41)

+×

10.5

⎟

R1

⎠

Internal Fixed Reference AGND to 0.2 V 1.0 2.0

External Reference Operation

The AD9444’s internal reference is trimmed to enhance the gain
accuracy of the ADC. An external reference may be more stable
over temperature, but the gain of the ADC is not likely to be

VIN+

improved. Figure 36 shows the typical drift characteristics of the
internal reference in both 1 V and 0.5 V modes.

When the SENSE pin is tied to AVDD, the internal reference is
disabled, allowing the use of an external reference. An internal
reference buffer loads the external reference with an equivalent
7 kΩ load. The internal buffer still generates the positive and

1Vp-p

VIN–

DIGITAL OUT = ALL 1s DIGITAL OUT = ALL 0s

negative full-scale references, REFT and REFB, for the ADC
core. The input span is always twice the value of the reference
voltage; therefore, the external reference must be limited to a
maximum of 1 V.

Analog Inputs

As with most new high speed, high dynamic range ADCs, the
analog input to the AD9444 is differential. Differential inputs
improve on-chip performance as signals are processed through
attenuation and gain stages. Most of the improvement is a result
of differential analog stages having high rejection of even-order
harmonics. There are also benefits at the PCB level. First,
differential inputs have high common-mode rejection of stray
signals, such as ground and power noise. Second, they provide
good rejection of common-mode signals, such as local oscillator
feedthrough. The specified noise and distortion of the AD9444
cannot be realized with a single-ended analog input, so such
configurations are discouraged. Contact ADI for recommenda­tions of other 14-bit ADCs that support single-ended analog
input configurations.

With the 1 V reference (nominal value, see the Internal Refer­ence Trim section), the differential input range of the AD9444’s
analog input is nominally 2 V p-p or 1 V p-p on each input
(VIN+ or VIN−).

The AD9444 analog input voltage range is offset from ground
by 3.5 V. Each analog input connects through a 1 kΩ resistor to
the 3.5 V bias voltage and to the input of a differential buffer.
The internal bias network on the input properly biases the
buffer for maximum linearity and range (see the Equivalent
Circuits section). Therefore, the analog source driving the
AD9444 should be ac-coupled to the input pins. The recom­mended method for driving the analog input of the AD9444 is
to use an RF transformer to convert single-ended signals to
differential (see Figure 44). Series resistors between the output
of the transformer and the AD9444 analog inputs help isolate
the analog input source from switching transients caused by the
internal sample-and-hold circuit. The series resistors, along with
the 1 kΩ resisters connected to the internal 3.5 V bias, must be
considered in impedance matching the transformers input. For
example, if R
with a 1:1 impedance ratio transformer, the input would match
a 50 Ω source with a full-scale drive of 10.0 dBm. The 50 Ω
impedance matching can also be incorporated on the secondary
side of the transformer, as shown in the evaluation board sche­matic (see Figure 47 and Figure 59).

Figure 42. Differential Analog Input Range for VREF = 1 V

ANALOG

INPUT

SIGNAL

Figure 43. Transformer-Coupled Analog Input Circuit

2 × VREF

3.5V

were set to 51 Ω and RS were set to 33 Ω, along

T

0.1

R

S

AIN

AD9444

R

S

µF

AIN

05089-046

R

T

ADT1–1WT

05089-045

Rev. 0 | Page 21 of 40

AD9444

CLOCK INPUT CONSIDERATIONS

Any high speed ADC is extremely sensitive to the quality of the
sampling clock provided by the user. A track-and-hold circuit is
essentially a mixer, and any noise, distortion, or timing jitter on
the clock is combined with the desired signal at the A/D output.
For that reason, considerable care was taken in the design of the
clock inputs of the AD9444, and the user is advised to give
careful thought to the clock source.

Typical high speed ADCs use both clock edges to generate a
variety of internal timing signals and, as a result, may be
sensitive to the clock duty cycle. Commonly a 5% tolerance is
required on the clock duty cycle to maintain dynamic perform­ance characteristics. The AD9444 contains a clock duty cycle
stabilizer (DCS) that retimes the nonsampling edge, providing
an internal clock signal with a nominal 50% duty cycle. As
shown in Figure 32, noise and distortion performance are nearly
flat for a 30% to 70% duty cycle with the DCS enabled. The DCS
circuit locks to the rising edge of CLK+ and optimizes timing
internally. This allows for a wide range of input duty cycles at
the input without degrading performance. Jitter in the rising
edge of the input is still of paramount concern and is not re­duced by the internal stabilization circuit. The duty cycle con­trol loop does not function for clock rates less than 30 MHz
nominally. The loop has a time constant associated with it that
needs to be considered in applications where the clock rate can
change dynamically, which requires a wait time of 1.5 µs to 5 µs
after a dynamic clock frequency increase (or decrease) before
the DCS loop is relocked to the input signal. During the time
period the loop is not locked, the DCS loop is bypassed, and the
internal device timing is dependant on the duty cycle of the
input clock signal. In such an application, it may appropriate to
disable the duty cycle stabilizer. In all other applications,
enabling the DCS circuit is recommended to maximize ac
performance.

the CLK+ and CLK− pins via a transformer or capacitors.
Figure 44 shows one preferred method for clocking the AD9444.
The clock source (low jitter) is converted from single-ended-to­differential using an RF transformer. The back-to-back Schottky
diodes across the transformer secondary limit clock excursions
into the AD9444 to approximately 0.8 V p-p differential. This
helps prevent the large voltage swings of the clock from feeding
through to other portions of the AD9444 and limits the noise
presented to the sample clock inputs.

If a low jitter clock is available, another option is to ac couple a
differential ECL/PECL signal to the encode input pins, as shown
in Figure 46.

CLOCK

SOURCE

Figure 44. Crystal Clock Oscillator, Differential Encode

ECL/

PECL

ADT1–1WT

0.1

µF

HSMS2812

DIODES

VT

0.1

µF

0.1µF

VT

Figure 45. Differential ECL for Encode

CLK+

AD9444

CLK–

ENCODE

AD9444

ENCODE

05089-048

05089-047

Jitter Considerations

High speed, high resolution ADCs are sensitive to the quality
of the clock input. The degradation in SNR at a given input
frequency (
(

t

) can be calculated using the following equation.

J

f

) and rms amplitude due only to aperture jitter

INPUT

SNR = 20 log[2πf

INPUT

× tJ]

The DCS circuit is controlled by the DCS MODE pin; a CMOS
logic low (AGND) on DCS MODE enables the duty cycle stabi­lizer, and logic high (AVDD1 = 3.3 V) disables the controller.

The AD9444 input sample clock signal must be a high quality,
extremely low phase noise source to prevent degradation of
performance. Maintaining 14-bit accuracy places a premium on
the encode clock phase noise. SNR performance can easily
degrade by 3 dB to 4 dB with 70 MHz analog input signals
when using a high jitter clock source. (See

AN-501, Aperture

Uncertainty and ADC System Performance, for complete
details.) For optimum performance, the AD9444 must be
clocked differentially. The sample clock inputs are internally
biased to ~2.2 V, and the input signal is usually ac-coupled into

Rev. 0 | Page 22 of 40

In the equation, the rms aperture jitter represents the root-mean
square of all jitter sources, which includes the clock input,
analog input signal, and ADC aperture jitter specification. IF
undersampling applications are particularly sensitive to jitter,
see Figure 46.

The clock input should be treated as an analog signal in cases
where aperture jitter may affect the dynamic range of the
AD9444. Power supplies for clock drivers should be separated
from the ADC output driver supplies to avoid modulating the
clock signal with digital noise. Low jitter, crystal-controlled
oscillators make the best clock sources. If the clock is generated
from another type of source (by gating, dividing, or other meth­ods), it should be retimed by the original clock at the last step.

AD9444

75

70

65

60

55

SNR (dBc)

50

45

40

1

Figure 46. SNR vs. Input Frequency and Jitter

INPUT FREQUENCY (MHz)

0.2ps

0.5ps

1.0ps

1.5ps

2.0ps

2.5ps

3.0ps

100010010

05089-049

POWER CONSIDERATIONS

Care should be taken when selecting a power source. The use of
linear dc supplies is highly recommended. Switching supplies
tend to have radiated components that may be received by the
AD9444. Each of the power supply pins should be decoupled as
closely to the package as possible using 0.1 µF chip capacitors.

The AD9444 has separate digital and analog power supply
pins. The analog supplies are denoted AVDD1 (3.3 V) and
AVDD2 (5 V) and the digital supply pins are denoted DRVDD.
Although the AVDD1 and DRVDD supplies may be tied
together, best performance is achieved when the supplies are
separate. This is because the fast digital output swings can
couple switching current back into the analog supplies. Note
that both AVDD1 and AVDD2 must be held within 5% of the
specified voltage.

The DRVDD supply of the AD9444 is a dedicated supply for the
digital outputs, in either LVDS or CMOS output modes. When
in LVDS mode, the DRVDD should be set to 3.3 V. In CMOS
mode, the DRVDD supply may be connected from 2.5 V to

3.6 V to be compatible with the receiving logic.

DIGITAL OUTPUTS

LVDS Mode

The off-chip drivers on the chip can be configured to provide
LVDS-compatible output levels via Pin 5 (OUTPUT MODE).
LVDS outputs are available when OUTPUT MODE is CMOS
logic high (or AVDD1 for convenience) and a 3.74 kΩ R
resistor is placed at Pin 7 (LVDSBIAS) to ground. Dynamic
performance, including both SFDR and SNR, is maximized
when the AD9444 is used in LVDS mode, and designers are
encouraged to take advantage of this mode. The AD9444 out­puts include complimentary LVDS outputs for each data bit
(DX+/DX−), the overrange output (OR+/OR−), and the output
data clock output (DCO+/DCO−). The R

resistor current is

SET

ratioed on-chip, setting the output current at each output equal

). A 100 Ω differential termina-

to a nominal 3.5 mA (11 ×

I

R

SET

SET

tion resistor placed at the LVDS receiver inputs results in a
nominal 350 mV swing at the receiver. LVDS mode facilitates
interfacing with LVDS receivers in custom ASICs and FPGAs
that have LVDS capability for superior switching performance
in noisy environments. Single point-to-point net topologies are
recommended with a 100 Ω termination resistor as close to the
receiver as possible. It is recommended to keep the trace length
less than 1 inch to 2 inches and to keep differential output trace
lengths as equal as possible.

CMOS Mode

In applications that can tolerate a slight degradation in dynamic
performance, the AD9444 output drivers can be configured to
interface with 2.5 V or 3.3 V logic families by matching DRVDD
to the digital supply of the interfaced logic. CMOS outputs are
available when OUTPUT MODE is CMOS logic low (or AGND
for convenience). In this mode, the output data bits are single­ended CMOS, DX, as is the overrange output, OR. The output
clock is provided as a differential CMOS signal, DCO+/DCO−.
Lower supply voltages are recommended to avoid coupling
switching transients back to the sensitive analog sections of the
ADC. The capacitive load to the CMOS outputs should be
minimized, and each output should be connected to a single
gate through a series resistor (220 Ω) to minimize switching
transients caused by the capacitive loading.

TIMING

The AD9444 provides latched data outputs with a pipeline delay
of 12 clock cycles. Data outputs are available one propagation
delay (t

) after the rising edge of CLK+. Refer to Figure 2 and

PD

Figure 3 for detailed timing diagrams.

OPERATIONAL MODE SELECTION

Data Format Select

The data format select (DFS) pin of the AD9444 determines
the coding format of the output data. This pin is 3.3 V CMOS
compatible, with logic high (or AVDD1, 3.3 V) selecting twos
complement, and DFS logic low (AGND) selecting offset binary
format. Table 10 summarizes the output coding.

Output Mode Select

The OUPUT MODE pin controls the logic compatibility,
as well as the pinout of the digital outputs. This pin is a CMOS
compatible input. With OUTPUT MODE = 0 (AGND), the
AD9444 outputs are CMOS-compatible and the pin assignment
for the device is defined in Table 8. With OUTPUT MODE = 1
(AVDD1, 3.3 V), the AD9444 outputs are LVDS-compatible and
the pin assignment for the device is defined in Table 7.

Duty Cycle Stabilizer

The DCS circuit is controlled by the DCS MODE pin; a CMOS
logic low (AGND) on DCS MODE enables the DCS, and logic
high (AVDD1, 3.3 V) disables the controller.

Rev. 0 | Page 23 of 40

AD9444

Table 10. Digital Output Coding

VIN+ − VIN−

Code

16383 1.000 0.500 11 1111 1111 1111 01 1111 1111 1111
8192 0 0 10 0000 0000 0000 00 0000 0000 0000
8191 −0.000122 −0.000061 01 1111 1111 1111 11 1111 1111 1111
0 −1.00 −0.5000 00 0000 0000 0000 10 0000 0000 0000

Input Span = 2 V p-p (V)

VIN+ − VIN−
Input Span = 1 V p-p (V)

Digital Output
Offset Binary (D9••••••D0)

Digital Output
Twos Complement (D9••••••D0)

EVALUATION BOARD

Evaluation boards are offered to configure the AD9444 in
either CMOS or LVDS mode. Each represents a recommended
configuration for using the device over a wide range of sample
rates and analog input frequencies. These evaluation boards
provide all the support circuitry required to operate the ADC in
its various modes and configurations. Complete schematics and
layout plots follow and demonstrate the proper routing and
grounding techniques that should be applied at the system level.

It is critical that signal sources with very low phase noise
(< 1 ps rms jitter) be used to realize the ultimate performance
of the converter. Proper filtering of the input signal, to remove
harmonics and lower the integrated noise at the input, is also
necessary to achieve the specified noise performance.

The evaluation boards are shipped with an ac to 6 V dc power
supply. The evaluation boards include low dropout regulators to
generate the various dc supplies required by the AD9444 and its
support circuitry. Separate power supplies are provided to iso­late the DUT from the support circuitry. Each input configura­tion can be selected by proper connection of various jumpers
(see Figure 47 to Figure 50 and Figure 59 to Figure 61).

Both the LVDS and CMOS versions of the evaluation board are
compatible with the high speed ADC FIFO evaluation kit (part
number HSC-ADC-EVALA-SC). The kit includes a high speed
data capture board that provides a hardware solution for captur­ing up to 32Ksamples of high speed ADC output data in a FIFO
memory chip (user upgradeable to 256K samples). Software is
provided to enable the user to download the captured data to a
PC via the USB port. This software also includes a behavioral
model of the AD9444 and many other high speed ADCs.

Behavioral modeling of the AD9444 is also available at

www.analog.com/ADIsimADC. The ADIsimA DC™ software

supports virtual ADC evaluation using ADI proprietary
behavioral modeling technology. This allows rapid comparison
between the AD9444 and other high speed ADCs, with or
without hardware evaluation boards.

The AD9444 LVDS evaluation board includes an on-board,
LVDS-to-CMOS translator, but the user may choose to remove
the translator and terminations to access the LVDS outputs
directly.

The CMOS evaluation board includes a buffer for the output
data and the DCO output clock of the AD9444.

Rev. 0 | Page 24 of 40

AD9444

LVDS EVALUATION BOARD SCHEMATICS

GND

8
7
6
5

P5

4
3
2
1

ENC

ENCODE

GND

R39

XX

GND

50Ω

R7

XTALINPUT

C92

0.1µF

C93

0.1µF

C44

10µF

+

VXTAL

5V

OPTIONAL ENCODE CIRCUITS

E47

E52

VDL

GND

DRVDD

GND

VCC

GND

5V

T3

C36

0.1µF

CR2

GND

ADT1-1WT

C42

6

123

GND

R36

XX

1

2

0.1µF

4

5

NC

C26

0.1µF

J1

ENCODE

GND

R37
XX

VXTAL

U6

ECLOSC

3

J5

VCC

E46

GND

SEC

PRI

GND

ENCB

50Ω

R8

XTALOUTB
8

OUTVCC

14

VXTAL

GND

XTALINPUTB

GND

R38

XX

R40

GND

R27
XX

R20
XX

XTALOUT

VXTAL

1

VEE ~OUT

7

GND

GND

H4
MTHOLE6

H3
MTHOLE6

H2
MTHOLE6

H1
MTHOLE6

D11_C/D7_YN

D11_T/D8_YN

D12_C/D9_YN

D12_T/D10_YN
D13_C/D11_YN

GND

DRVDD

DOR_C/D13_YN

DOR_T/DOR_YN

GND
VCC
GND
VCC
VCC
VCC
VCC
VCC
VCC
VCC
GND
GND

R9

R12

1kΩ

1kΩ

VCC

GND

E39

VCC

XX

XTALINPUTB

XTALINPUT

VXTAL

VCC

JN00158

FOR VECTRON XTAL

XX

R17

E38

XTALOUTB

OUTPUTB

D3_CN

D3_TN

D4_CN

D4_TN

D5_CN

D5_TN

D6_CN

64

12

E24

R3

E20

DRN

DCO+

U1

AGND

GND

EXTREF

63

PIN DEFINITIONS

13

C3

0.1µF

EXTREF

DRVDD

DRBN

62

DCO–

DRVDD

LVDS/CMOS

REFT

REFB

14

0.1µF

10µF

C24

0.1µF

GND

3.8kΩ

C51

D6_TN

GND

60

61

D6–

D6+

DRGND

AGND

AVDD1

AVDD1

15

16

17

VCC

VCC

GND

C2

C9

0.1µF

GND

+
C39

10µF

GND

R2

GND

18

GND

D5+

AVDD1

VCC

DRVDD

GND

51

52

5556575859

53

54

D5–

D4–

VIN+

21

R28
33Ω

TOUT

ADT1-1WT

GND

DRVDD

VIN–

22

624

153

D3+

DRGND

D2+
D2–

DRGND

DRVDD

D1+
D1–
D0+

(LSB) D0–

AVDD1
AVDD1
AVDD2
AVDD2
AVDD1

CLK–

CLK+
AVDD1
AVDD1

AGND
AVDD2
AVDD2
AVDD2
AVDD2
AVDD1
AVDD1

AGND

AVDD1

23

24

25

VCC

GND

R4

36Ω

GND

C12

0.1µF

NC

R5

GND

D3–

50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33

C1

32
31
30
29
28
27
26

AVDD1

VCC

C13

20pF

OPTIONAL

R13

xx

TOUTB

TINB

C5

L1

100Ω

xx

J4

C91

0.1µF

R6

E15

0.1µF

D2_TN
D2_CN
GND
DRVDD
D1_TN
D1_CND13_T/D12_YN
D0_TN
D0_CN
VCC
VCC

C40

0.1µF

5V

33Ω
R35

5V

GND

VCC
ENCB
ENC
VCC
VCC

GND

VCC
VCC

GND

36Ω

ANALOG

GND

D4+

AVDD2

AGND

20

19

5V

GND

T5

GND

72

73

74

75

D10–

D10+

DRVDD

76

D11–

77

D11+

78

D12–

79

D12+

80

D13–

81

D13+ (MSB)

82

DRGND

83

DRVDD

84

OR–

85

OR+

86

AGND

87

AVDD1

88

AGND

89

AVDD1

90

AVDD1

91

AVDD1

92

AVDD1

93

AVDD1

94

AVDD1

95

AVDD1

96

AGND

97

AGND

98

AVDD1

99

AGND

100

DCS MOD

EPAD

101

GND

E40

GND

XTALOUT

456

OUTPUT

U2

GNDNCE/D

321

R19

XX

GND

GND

XX

R18

DRGND

AVDD1

DNC

DNC

DNC

234

1

1kΩ

R15

VCC

E3

E1

VCC

GND

65

66

686970

71

67

D9–

D8–

D9+

D7–

D8+

D7+

DRGND

AD9444

OUTPUT MODE

DFS

LVDSBIAS/DNC

AVDD1

AVDD1

SENSE

VREF

7

9

5

8

6

10

11

VCC

VCC

1kΩ

R14

GND

C86

0.1µF
GND

GND

E25

E27

E26

E41

VCC

R1

GND

3.8kΩ

E2

GND

3.8kΩ

D7_CN

D7_T/D0_YN

D8_C/D1_YN

D8_T/D2_YN

D9_C/D3_YN

D9_T/D4_YN

D10_C/D5_YN

D10_T/D6_YN

DRVDD

VXTAL

FOR VF XTAL

05089-050

Figure 47. LVDS Mode Evaluation Board Schematic

Rev. 0 | Page 25 of 40

AD9444

POWER OPTIONS

VDL

DRVDD

ADP3338

U4

3.3V

4

OUT

+

C57
10µF

GND

+

C88
10µF

4

ADP3338

OUT

U3

3.3V

GND

OUT1

GND

OUT1

1

GND

2
3

IN

1
2
3

IN

VDL

VCC

VIN

+

C1
10µF

GND

GND

DRVDD

VIN

+

C34
10µF

+

C87
10µF

GND

5V

+

C89
10µF

4

4

OUT

OUT

ADP3338

U15

3.3V

ADP3338

U14

5V

GND

OUT1

GND

OUT1

P4

1

GND

2

VCC

3

IN

+

1
2
3

IN

+

C6
10µF

GND

GND

C4
10µF

VIN

5V

VIN

PJ-102A

2

2

GND

3

3

1

1

+

C33
10µF

GND

VIN

GND

DRVDD

GND

5V

GND

VCC

GND

VCC

GND

05089-051

GND

GND

GND

Figure 48. LVDS Mode Evaluation Board Schematic (Continued)

+

+

C65
10µF

+

C56
10µF

C64
10µF

C10
XX

C43

0.1µF

C47

0.1µF

C85

0.1µF

C11
XX

C23

0.1µF

C53

0.1µF

C35

0.1µF

C14
XX

C22

0.1µF

C52

0.1µF

C32

0.1µF

C17
XX

C21

0.1µF

C58

0.1µF

C30

0.1µF

C16
XX

C20

0.1µF

GND

5V

C28

0.1µF

C15
XX

C27

0.1µF

C31
XX

DRVDD

GND

C71XXC72XXC73XXC62

C50

C48

0.1µF

0.1µF

C38

C37

XX

XX

C69XXC70XXC45XXC49XXC59

C60

0.1µF

C29
XX

XX

C61

0.1µF

C19
XX

EXTREF

GND

C46

0.1µF

C18
XX

C75

0.1µF

C90
XX

XX

+

C55
10µF

P19

GND

05089-052

Figure 49. LVDS Mode Evaluation Board Schematic (Continued)

Rev. 0 | Page 26 of 40

AD9444

GND

GND

DOR_C/D13_YN

D13_C/D11_YN

D12_C/D9_YN
D11_C/D7_YN
D10_C/D5_YN

D9_C/D3_YN
D8_C/D1_YN

D7_CN

DRBN
D6_CN
D5_CN
D4_CN
D3_CN
D2_CN
D1_CN
D0_CN

GND

U7

SN75LVDS386

DOR_T/DOR_YN

P6

C40MS

39

P39

37

P37

35

P35

33

P33

31

P31

29

P29

27

P27

25

P25

23

P23

21

P21

19

P19

17

P17

15

P15

13

P13

11

P11

9

P9

7

P7

5

P5

3

P3

1

P1

P40
P38
P36
P34
P32
P30
P28
P26
P24
P22
P20
P18
P16
P14
P12
P10

40

GND

38
36

GND

34

DOR_T/DOR_YN

32

D13_T/D12_YN

30

D12_T/D10_YN

28

D11_T/D8_YN

26

D10_T/D6_YN

24

D9_T/D4_YN

22

D8_T/D2_YN

20

D7_T/D0_YN

18

DRN

16

D6_TN

14

D5_TN

12

D4_TN

10

D3_TN

8

P8
P6
P4
P2

D2_TN

6

D1_TN

4

D0_TN

2

GND

DOR_C/D13_YN

D13_T/D12_YN

D13_C/D11_YN

D12_T/D10_YN

D12_C/D9_YN

D11_T/D8_YN

D11_C/D7_YN

D10_T/D6_YN

D10_C/D5_YN

D9_T/D4_YN

D9_C/D3_YN

D8_T/D2_YN

D8_C/D1_YN

D7_T/D0_YN

D7_CN

DRN

DRBN

D6_TN

D6_CN

D5_TN

D5_CN

D4_TN

D4_CN

D3_TN

D3_CN

D2_TN

D2_CN

D1_TN

D1_CN

D0_TN

D0_CN

1

A1A

2

A1B

3

A2A

4

A2B

5

A3A

6

A3B

7

A4A

8

A4B

9

B1A

10

B1B

11

B2A

12

B2B

13

B3A

14

B3B

15

B4A

16

B4B

17

C1A

18

C1B

19

C2A

20

C2B

21

C3A

22

C3B

23

C4A

24

C4B

25

D1A

26

D1B

27

D2A

28

D2B

29

D3A

30

D3B

31

D4A

32

D4B

GND
VCC1
VCC2
GND1

ENA

A1Y
A2Y
A3Y
A4Y

ENB

B1Y
B2Y
B3Y

B4Y
GND2
VCC3
VCC4
GND3

C1Y

C2Y

C3Y

C4Y

ENC

D1Y

D2Y

D3Y

D4Y

END
GND4
VCC5
VCC6
GND5

64

GND

63

VDL

62

VDL

61

GND

60

VDL

59
58
57
56
55

VDL

54
53
52
51
50

GND

49

VDL

48

VDL

47

GND

46

DRP

45
44
43
42

VDL

41
40
39
38
37

VDL

36

GND

35

VDL

34

VDL

33

GND

RZ5

RSO16ISO

R1

1

R2

2

R3

3

R4

4

R5

5

R6

6

R7

7

R8

8

RSO16ISO

R1

1

R2

2

R3

3

R4

4

R5

5

R6

6

R7

7

R8

8

RZ4

220

220

16

ORO

15

D13O

14

D12O

13

D11O

12

D10O

11

D9O

10

D8O

9

D7O

16

D6O

15

D5O

14

D4O

13

D3O

12

D2O

11

D1O

10

D0O

9

GND

40

P40

38

P38

36

P36

34

P34

32

P32

30

P30

28

P28

26

P26

24

P24

22

P22

20

P20

18

P18

16

P16

14

P14

12

P12

10

P10

8

P8

6

P6

4

P4

2

P2

C40MS

39

P39
P37
P35
P33
P31
P29
P27
P25
P23
P21
P19
P17
P15
P13
P11

P9
P7
P5
P3
P1

P3

GND

37

DRO

35

GND

33

D13O

31

D12O

29

D11O

27

D10O

25

D9O

23

D8O

21

D7O

19

D6O

17

D5O

15

D4O

13

D3O

11

D2O

9

D1O

7

D0O

5

ORO

3
1

GND

VDL

GND

E32

E43

E34

VDL

GND

GND

GND

00

R53

XORN

+

C76
10µF

74VCX86

1

1A

2

1B

4

2A

5

2B

9

3A

10

3B

12

4A

13

4B

U10

C97

0.1µF

1Y

2Y

3Y

4Y

C82

0.1µF

3
6

00

8

R52

11

PWR

14
7

GND

C80

0.1µF810.1µF

DRO

VDL
GND

05089-053

Figure 50. LVDS Mode Evaluation Board Schematic (Continued)

Rev. 0 | Page 27 of 40

AD9444

Figure 51. LVDS Mode Evaluation Board Layout, Primary Side

Figure 52. LVDS Mode Evaluation Board Layout, Secondary Side

05089-057

05089-058

Figure 54. LVDS Mode Evaluation Board Layout, Ground Plane 2

Figure 55. LVDS Mode Evaluation Board Layout, Power Plane 1

05089-060

05089-061

Figure 53. LVDS Mode Evaluation Board Layout, Ground Plane 1

05089-059

Rev. 0 | Page 28 of 40

Figure 56. LVDS Mode Evaluation Board Layout, Power Plane 2

05089-062

AD9444

05089-064

Figure 57. LVDS Mode Evaluation Board Layout, Primary Silkscreen

05089-063

Figure 58. LVDS Mode Evaluation Board Layout, Secondary Silkscreen

Rev. 0 | Page 29 of 40

AD9444

LVDS MODE EVALUATION BOARD BILL OF MATERIALS (BOM)

Table 11.

Item Qty. REFDES Description Manufacturer MFG_PART_NO

1 1 AD9444PCB PCB, AD9444 LVDS Engineering Evaluation Board PCSM AD9444LVDSCUSTREVC
2 16

3 38

4 1 C51 Capacitor, Ceramic 10 µF 6.3 V X5R 0805 KEMET C0805C106K9PACTU
5 1 CR2 Diode, Dual Schottky HSMS2812, SOT-23, 30 V, 20 mA Panasonic MA716-(TX)
6 17

7 2 J1, J4 Connector, Gold, Male, Coaxial, SMA, Vertical Johnston Comp. 142-0701-201
8 1 L1 10 nH Inductor Coilcraft 0603CJ-10NXGBU
9 1 P3 Header, 40-Pin, Male, 40-Pin Right Angle Samtec TSW-120-08-T-D-RA
10 1 P4 Power Jack Swithcraft RAPC722
11 1 R3 Resistor, 3.6 kΩ 1/16 W 1% 0402 SMD Panasonic ERJ-2GEJ362X
12 2 R4, R6 Resistor, 36 Ω 1/16 W 5% 0402 SMD Panasonic ERJ-2GEJ360X
13 1 R8 Resistor, 49.9 Ω 1/16 W 1% 0402 SMD Panasonic ERJ-2RKF49R9X
14 4

15 2 R28, R35 Resistor, 33 Ω 1/16 W 5% 0402 SMD Panasonic ERJ-2GEJ330X
16 3

17 2 RZ4, RZ5 22 Ω Resistor Array, 16 Term CTS Corp. 742163220JTR
18 2 T3, T5 Transformer, ADT1-1WT, CD542, ADT1-1WT Mini-Circuits ADT1-1WT
19 1 U1 14-Bit, 80 MSPS ADC ADI AD9444BSVZ-80
20 3 U3, U4, U15 3.3 V Voltage Regulator ADI ADP3338-3.3 V
21 1 U14 5 V Voltage Regulator ADI ADP3338-5.0 V
22 1 U6 Clock Oscillator, 80 MHz CTS Reeves MX045-80
23 1 U7 LVDS-to-CMOS Translator with 100 Term Texas Instruments SN75LVDT386DGG
24 1 U10 2 Input XOR Gate Fairchild 74VCX86M
25 4 U6 Pin Sockets, Closed End AMP 5-330808-3

C1, C4, C6,
C33, C34,
C39, C44,
C55 to C57,
C64, C65,
C76, C87 to
C89

C2, C3, C5,
C9, C12, C20
to C24, C26
to C28, C30,
C32, C35,
C40, C42,
C43, C46 to
C48, C50,
C52, C53,
C58, C60,
C61, C75,
C80 to C82,
C85, C86,
C91 to C93,
C97

E1 to E3, E24,
to E27, E32,
E34, E38,
E39, E40,
E41, E43,
E46, E47, E52

R9, R12, R14,
R15

R39, R52,
R53

Capacitors, Tantalum, SMT BCAPTAJC, 10 µF, 16 V, 10% KEMET T491C106K016AS

Capacitors, 0.1 µF 10 V Ceramic X5R 0402 Panasonic ECJ-0EB1A104K

40-Pin Breakable Header 3M 2340-611TN

Resistor, 1.00 kΩ 1/16 W 1% 0402 SMD Panasonic ERJ-2RKF1001X

Resistor, 0 Ω 1/16 W 5% 0402 SMD Panasonic ERJ-2GE0R00X

Rev. 0 | Page 30 of 40

AD9444

Item Qty. REFDES Description Manufacturer MFG_PART_NO

26 24

C10, C11,
C13, to C19,
C29, C31,
C36 to C38,
C45, C49,
C59, C62,
C69, C70 to

C73, C90
27 1 J51 Connector, Gold, Male, Coaxial, SMA, Vertical Johnston Comp. 142-0701-201
28 2 P5, P61 Power Connectors Weiland
29 1

30 1

R1, R2, R5,

1

R7, R13

R17 to R20,

R27, R36 to

R38, R40
31 5 U21 XO Select Vectron

1

Parts not placed.

Capacitors, Select 10 V Ceramic X5R 0402 Panasonic

1

Resistors, Select 1/16 W 1% 0402 SMD Panasonic

Resistors, Select 1/16 W 1% 0402 SMD Panasonic

1

Rev. 0 | Page 31 of 40

AD9444

CMOS EVALUATION BOARD SCHEMATICS

GND

8

VDL

7

GND

6

DRVDD

5

GND

P5

4

VCC

3

GND

2
1

5V

H4
MTHOLE6

H3
MTHOLE6

H2
MTHOLE6

H1

R39

MTHOLE6

ENC

3

CR2

C42

6

T3

123

5

ADT1-1WT

NC

XX

C36

0.1µF

XTALINPUT

J5

GND

C96

0.1µF

C92

0.1µF

C93

0.1µF

C44

10µF

+

VXTAL

5V

VCC

GND

ENCODE

GND

GND

50Ω

R7

OPTIONAL ENCODE CIRCUITS

E52

E47

E46

ENCB

1

2

GND

0.1µF

4

SEC

PRI

C26

0.1µF

50Ω

R8

J1

GND

GND

R37
XX

R36

XX

XTALOUTB

VXTAL

8

OUTVCC

U6

ECLOSC

GND

14

VXTAL

D11C/D7YN
D11T/D8YN
D12C/D9YN

D12T/D10YN
D13C/D11YN
D13T/D12YN

GND

DRVDD

DORC/D13Y

DORT/DORY

GND
VCC
GND
VCC
VCC
VCC
VCC
VCC
VCC
VCC
GND
GND

R9

R12

1kΩ

1kΩ

VCC

GND

GND

GND

XTALINPUTB

XTALOUT

1

VEE ~OUT

7

GND

E39

E40

E38

VCC

GND

R38

XX

R40

XX

XTALINPUTB

GND

VXTAL

GND

R27
XX

R20
XX

XTALINPUT

XTALOUT

XTALOUTB

VXTAL

456

VCC

OUTPUT

OUTPUTB

JN00158

GNDNCE/D

321

GND

FOR VECTRON XTAL

XX

R17

COUTB

DRVDD

GND

73

74

75

DRVDD

R21

1

AVDD1

234

1kΩ

VCC

DRGND

DNC

76

D7

77

D8

78

D9

79

D10

80

D11

81

D12

82

DRGND

83

DRVDD

84

(MSB) D13

85

OR

86

AGND

87

DRVDD

88

AGND

89

AVDD1

90

AVDD1

91

AVDD1

92

AVDD1

93

AVDD1

94

AVDD1

95

AVDD1

96

AGND

97

AGND

98

AVDD1

99

AGND

100

DCS MODE
EPAD

101

U2

R19

XX

GND

XX

R18

D9C/D3Y

D9T/D4Y

D10C/D5YN

D10T/D6YN

72

71

D6D5D4D3D2

DNC

DNC

OUTPUT MODE

DFS

5

6

R15

1kΩ

GND

E3

E2

E1

VCC

GND

D8T/D2Y

LVDSBIAS

7

COUT

66

10

E25

D7T/D0Y

65

D0 (LSB)

SENSE

11

E27

E41

3.8kΩ

REFERENCE

64

63

DNC

DCO+

U1

AD9444

VREF

AGND

13

12

GND

C3

0.1µF

GND

E24

EXTREF

GND

R1

R3

3.8kΩ

EXTREF

INPUT

E20

DRVDD

GND

60

61

62

DNC

DNC

DRVDD

REFB

C78

0.1µF

C51
10µF

C2

+
C39

R2

3.8kΩ

15

DRGND

AGND

GND

0.1µF

GND

GND

DNC

AVDD1

AVDD1

AVDD1

16

18

17

VCC

VCC

VCC

C9

GND

GND

10µF

DCO–

LVDS/CMOS

PIN DEFINITIONS

REFT

14

0.1µF

19

DNC

AVDD2

5V

GND

DRVDD

51

52

5556575859

53

54

DNC

DNC

DNC

DNC

DRVDD

DRGND

50

DNC

49

DNC

48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26

C13

20pF

R13

xx

TOUTB

TINB

L110NH

C5

C91

0.1µF

R6

E15

0.1µF

GND
DRVDD

VCC
VCC

C40

0.1µF

5V

33Ω
R35

5V

GND

05089-054

VCC
ENCB
ENC
VCC
VCC

GND

VCC
VCC

GND

36Ω

ANALOG

GND

DRGND
DRVDD

DNC
DNC
DNC

DNC
AVDD1
AVDD1
AVDD2
AVDD2
AVDD1

CLK–

CLK+
AVDD1
AVDD1

C1

AGND
AVDD2
AVDD2
AVDD2
AVDD2
AVDD1
AVDD1

AGND

VIN+

VIN–

AGND

AVDD1

AVDD1

20

23

21

22

24

25

VCC

VCC

GND

GND

OPTIONAL

R28
33Ω

R4

36Ω

GND

C12

0.1µF

TOUT

CT

624

T5

153

PRI SEC

ADT1-1WT

NC

GND

100Ω

xx

R5

J4

GND

GND

D8C/D1Y

686970

67

D1

DRGND

AVDD1

AVDD1

9

8

VCC

VCC

E26

VCC

GND

EXTERNAL

VXTAL

FOR VF XTAL

Figure 59. CMOS Mode Evaluation Board Schematic

Rev. 0 | Page 32 of 40

AD9444

VDL

DRVDD

+

+

C57
10µF

GND

C88
10µF

4

4

OUT

OUT

ADP3338

U8

3.3V

ADP3338

U3

3.3V

GND

OUT1

GND

OUT1

1

GND

2

VDL

3

IN

C1

+

10µF

GND

1

GND

2

DRVDD

3

IN

C34

+

10µF

VIN

VIN

VCC

C87

+

10µF

GND

5V

C89

+

10µF

4

4

OUT

OUT

ADP3338

U15

3.3V

ADP3338

U14

5V

GND

OUT1

GND

OUT1

P4

1

GND

2

VCC

3

IN

C6

+

10µF

GND

1

GND

2

5V

3

IN

C4

+

10µF

PJ-102A

VIN

VIN

2

2

GND

3

3

1

1

+

C33
10µF

GND

VIN

GND

GND

GND

GND

Figure 60. CMOS Mode Evaluation Board Schematic (Continued)

05089-055

Rev. 0 | Page 33 of 40

AD9444

DORT/DORY

DORC/D13Y

D13T/D12Y
D13C/D11Y
D12T/D10Y

D12C/D9Y
D11T/D8Y
D11C/D7Y

D10T/D6Y
D10C/D5Y

D9T/D4Y

D9C/D3Y

D8T/D2Y

D8C/D1Y

D7T/D0Y

RZ1

RSO16ISO
1
2
3
4
5
6
7
8

RSO16ISO
1
2
3
4
5
6
7
8

COUTB

COUT

VDL

GND

VDL

GND

R1
R2
R3
R4
R5
R6
R7
R8

R1
R2
R3
R4
R5
R6
R7
R8

RZ4

220

16
15
14
13
12
11
10
9

220RZ2

16
15
14
13
12
11
10
9

NOT PLACED

E42

E31

E49

E45

E32

E30

00

R50

00

R16

XOR2IN

XOR2IN

GND

GATE2

GND

VDL

GND

GND

VDL

GND

XORZIN

25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48

1
2
4
5

9
10
12
13

U5

SN74LVCH16373A

Q = OUTPUT

D = INPUT

LE2
2D8
2D7
GND GND
2D6
2D5
VCC
2D4
2D3
GND
2D2
2D1
1D8
1D7
GND
1D6
1D5
VCC
1D4
1D3
GND
1D2
1D1
LE1

74VCX86
1A
1B
2A
2B
3A
3B
4A
4B

OE2

2Q8
2Q7

2Q6
2Q5

VCC

2Q4
2Q3

GND

2Q2
2Q1
1Q8
1Q7

GND

1Q6
1Q5

VCC

1Q4
1Q3

GND

1Q2
1Q1

OE1

U4

1Y

2Y

3Y

4Y

P3

C40MS

P39
P37
P35
P33
P31
P29
P27
P25
P23
P21
P19
P17
P15
P13
P11

39

GND

37

DRM

35

GND

33

D13M

31

D12M

29

D11M

27

D10M

25

D9M

23

D8M

21

D7M

19

D6M

17

D5M

15

D4M

13

D3M

11

D2M

9

P9
P7
P5
P3
P1

D1M

7

D0M

5

ORM

3
1

40

220

RZ5

RSO16ISO

R1

1

24

GND

23
22
21

GND

20
19
18

VDL

17
16
15

GND

14
13
12
11
10

GND

9
8
7

VDL

6
5
4

GND

3
2
1

GND

3
6

8
11

PWR

14

GND

7

VDL
GND

00

R42

DRM

R41

2
3
4
5
6
7
8

RSO16ISO
1
2
3
4
5
6
7
8

00

GATE

R14

00

R2
R3
R4
R5
R6
R7
R8

R1
R2
R3
R4
R5
R6
R7
R8

RZ4

16

ORM

15

D13M

14

D12M

13

D11M

12

D10M

11

D9M

10

D8M

9

D7M

220RZ5

16

D6M

15

D5M

14

D4M

13

D3M

12

D2M

11

D1M

10

D0M

9

GND GND

DRM

P40

38

P38

36

P36

34

P34

32

P32

30

P30

28

P28

26

P26

24

P24

22

P22

20

P20

18

P18

16

P16

14

P14

12

P12

10

P10

8

P8

6

P6

4

P4

2

P2

VDL

GND

U10

+

C66

C25

C41

10µF

0.1µF

0.1µF

C24

0.1µF

C68

0.1µF

C67

0.1µF630.01µF

Figure 61. CMOS Mode Evaluation Board Schematic (Continued)

Rev. 0 | Page 34 of 40

05089-056

AD9444

05089-068

Figure 62. CMOS Mode Evaluation Board Layout, Primar y Side

05089-065

Figure 65. CMOS Mode Evaluation Board Layout, Ground Plane 2

Figure 63. CMOS Mode Evaluation Board Layout, Secondary Side

Figure 64. CMOS Mode Evaluation Board Layout, Ground Plane 1

05089-066

05089-067

Rev. 0 | Page 35 of 40

Figure 66. CMOS Mode Evaluation Board Layout, Power Plane 1

Figure 67. CMOS Mode Evaluation Board Layout, Power Plane 2

05089-069

05089-070

AD9444

Figure 68. CMOS Mode Evaluation Board Layout, Primary Silkscreen

05089-071

Figure 69. CMOS Mode Evaluation Board Layout, Secondary Silkscreen

05089-072

Rev. 0 | Page 36 of 40

AD9444

CMOS MODE EVALUATION BOARD BILL OF MATERIALS (BOM)

Table 12.

Item Qty. REFDES Description Manufacturer MFG_PART_NO

1 1 AD9444PCB PCB, AD9444 LVDS Evaluation Board PCSM AD9444LVDSCUSTREVC
2 16

C1, C4, C6, C33, C34,
C39, C44, C55 to
C57, C64 to C66,
C87 to C89

Capacitors, Tantalum, SMT BCAPTAJC, 10 µF, 16 V, 10% KEMET T491C106K016AS

3 32

4 5

5 1 C51 Capacitor, Ceramic 10 µF 6.3 V X5R 0805 KEMET C0805C106K9PACTU
6 1 CR2 Diode, Dual Schottky HSMS2812, SOT-23, 30 V, 20 mA Panasonic MA716-(TX)
7 20

8 2 J1, J4 Connector, Gold, Male, Coaxial, SMA, Vertical Johnston Comp. 142-0701-201
9 1 L1 10 nH O402 Inductor Coilcraft 0402CS-10NX_B_
10 1 P3 Header, 40-Pin, Male, 40-Pin Right Angle Samtec TSW-120-08-T-D-RA
11 1 P4 Power Jack Swithcraft RAPC722
12 1 R3 Resistor, 3.6 kΩ 1/16 W 1% 0402 SMD Panasonic ERJ-2GEJ362X
13 2 R4, R6 Resistors, 36 Ω 1/16 W 5% 0402 SMD Panasonic ERJ-2GEJ360X
14 1 R8 Resistor, 49.9 Ω 1/16 W 1% 0402 SMD Panasonic ERJ-2RKF49R9X
15 4 R9, R12, R15, R21 Resistors, 1.00 kΩ 1/16 W 1% 0402 SMD Panasonic ERJ-2RKF1001X
16 2 R14, R50 Resistors, 0 Ω 1/10 W 5% 0603 SMD Panasonic ERJ-3GEY0R00V
17 2 R28, R35 Resistors, 33 Ω 1/16 W 5% 0402 SMD Panasonic ERJ-2GEJ330X
18 1 R39 Resistor, 0 Ω 1/16 W 5% 0402 SMD Panasonic ERJ-2GE0R00X
19 4 RZ1 to RZ3, RZ6 220 Ω Resistor Array, 16 Term CTS Corp. 742163221JTR
20 2 T3, T5 Transformer, ADT1-1WT, CD542, ADT1-1WT Mini-Circuits ADT1-1WT
21 1 U1 14-Bit, 80 MSPS ADC ADI AD9444BSVZ-80
22 4 U3, U8, U15 3.3 V Voltage Regulator ADI ADP3338-3.3 V
23 1 U14 5 V Voltage Regulator ADI ADP3338-5.0 V
24 1 U5 16-Bit Flip Flop Fairchild 74LVTH162374
25 4 U6 Pin Sockets, Closed End AMP 5-330808-3

C2, C3, C5, C9, C12,
C20 to C23, C26 to
C28, C30, C32, C35,
C40, C42, C43, C46 to
C48, C50, C52, C53,
C58, C60, C61, C75,
C78, C85, C91, C92

C24, C25, C41, C67,
C68

E1 to E3, E24 to E27,
E30 to E32, E38 to
E42, E45 to E47,
E49, E52

Capacitors, 0.1 µF 10 V Ceramic X5R 0402 Panasonic ECJ-0EB1A104K

Capacitors, 0.1 µF 16 V Ceramic X7R 0603 Panasonic ECJ-1VB1C104K

40-Pin Breakable Header 3M 2340-611TN

Rev. 0 | Page 37 of 40

AD9444

Item Qty. REFDES Description Manufacturer MFG_PART_NO

26 26

C10, C11, C13, C14 to
C19, C29, C31, C36 to
C37, C38, C45, C49,
C59, C62,C69, C70 to

C73, C90, C93, C96
27 1 J51 Connector, Gold, Male, Coaxial, SMA, Vertical Johnston Comp. 142-0701-201
28 15

R1,R2,R5,R7, R13,

R17 to R20, R27,

R36 to R40

1

29 3 R16, R41, R421 Resistors, Select 1/16 W 5% 0603 SMD Panasonic
30 1 C631 Capacitor, Select 10 V Ceramic X5R 0603 Panasonic
31 1 U41 XOR 74VCX86D Fairchild 74VCX86D
32 2 P5, P61 Power Connectors Weiland

1

Parts not placed.

Capacitors, Select 10 V Ceramic X5R 0402 Panasonic

1

Resistors, Select 1/16 W 1% 0402 SMD Panasonic

Rev. 0 | Page 38 of 40

AD9444

2

F

L

E

OUTLINE DIMENSIONS

1.20

0.75
MAX

0.60

0.45

SEATING

PLANE

0.20

0.09

NOTES

1. CENTER FIGURES ARE TYPICAL UNLESS OTHERWISE NOTED.
. THE PACKAGE HAS A CONDUCTIVE HEAT SLUG TO HELP DISSIPATE HEAT AND ENSURE RELIABLE OPERATION O

THE DEVICE OVER THE FULL INDUSTRIAL TEMPERATURE RANGE. THE SLUG IS EXPOSED ON THE BOTTOM OF
THE PACKAGE AND ELECTRICALLY CONNECTED TO CHIP GROUND. IT IS RECOMMENDED THAT NO PCB SIGNA
TRACES OR VIAS BE LOCATED UNDER THE PACKAGE THAT COULD COME IN CONTACT WITH THE CONDUCTIV

SLUG. ATTACHING THE SLUG TO A GROUND PLANE WILL REDUCE THE JUNCTION TEMPERATURE OF THE

DEVICE WHICH MAY BE BENEFICIAL IN HIGH TEMPERATURE ENVIRONMENTS.

3. THE EXPOSED HEAT SINK SOLDERED TO THE GROUND PLANE IS REQUIRED FOR THE 100-LEAD TQFP/EP.

1

25

26 50

7°

3.5°
0°

Figure 70. 100-Lead Thin Quad Flat Package, Exposed Pad [TQFP_EP]

16.00 SQ

14.00 SQ

76100

75

TOP VIEW

(PINS DOWN)

51

0.50 BSC

COMPLIANT TO JEDEC STANDARDS MS-026AED-HD

0.27

0.22

0.17

0.15

0.05

75

51

1.05

1.00

0.95

COPLANARITY

0.08

(SV-100-1)

Dimensions shown in millimeters

76 100

BOTTOM VIEW

(PINS UP)

CONDUCTIVE

HEAT SINK

6.50

NOM

1

25

2650

ORDERING GUIDE

Model Temperature Range Package Description Package Outline

AD9444BSVZ-80
AD9444-CMOS/PCB CMOS Mode Evaluation Board
AD9444-LVDS/PCB LVDS Mode Evaluation Board

1

Z = Pb-free part.

1

–40°C to +85°C 100-Lead TQFP_EP SV-100-1

Rev. 0 | Page 39 of 40

AD9444

NOTES

© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.

D05089–0–10/04(0)

Rev. 0 | Page 40 of 40