Datasheet AD9048 Datasheet (Analog Devices)

Monolithic 8-Bit

1

R

2

127

R

R/2

R/2

128

R

254

255

R

E
N
C
O
D

I
N
G

L
O
G

I
C

13

14

15

16

1

2

3

4

28
23
18

12

27

26

17

19 256 10

7

8 9

11

5

L
A
T
C
H

V

CC

V

EE

DGND AGND

D1 (MSB)
D2
D3
D3
D5
D6
D7
D8 (LSB)

NLINV

NMINV

V

IN

R

T

R

M

R

B

CONVERT

AD9048

a

FEATURES
35 MSPS Encode Rate
16 pF Input Capacitance
550 mW Power Dissipation
Industry-Standard Pinouts
MIL-STD-883 Compliant Versions Available

APPLICATIONS
Professional Video Systems
Special Effects Generators
Electro-Optics
Digital Radio
Electronic Warfare (ECM, ECCM, ESM)

GENERAL DESCRIPTION

The AD9048 is an 8-bit, 35 MSPS flash converter, made on a
high speed bipolar process, which is an alternate source for the
TDC1048 unit, offers enhancements over its predecessor.
Lower power dissipation makes the AD9048 attractive for a
variety of system designs.

Because of its wide bandwidth, it is an ideal choice for real-time
conversion of video signals. Input bandwidth is flat with no
missing codes.

Clocked latching comparators, encoding logic and output buffer
registers operating at minimum rates of 35 MSPS preclude a
need for a sample-and-hold (S/H) or track-and-hold (T/H) in
most system designs using the AD9048. All digital control in­puts and outputs are TTL compatible.

Devices operating over two ambient temperature ranges and
with two grades of linearity are available. Linearities of either

0.5 LSB or 0.75 LSB can be ordered for a commercial range

of 0°C to +70°C or extended case temperatures of –55°C to
+125°C.

Video A/D Converter

AD9048

FUNCTIONAL BLOCK DIAGRAM

Commercial versions are packaged in 28-lead DIPs; extended
temperature versions are available in ceramic DIP and ceramic
LCC packages. Both commercial units and MIL-STD-883 units
are standard products.

The AD9048 A/D converter is available in versions compliant
with MIL-STD-883. Refer to the Analog Devices Military Prod-
ucts Databook or current AD9048/883B data sheet for detailed
specifications.

REV. C

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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 1999

AD9048–SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

1

(typical with nominal supplies unless otherwise noted)

VCC to DGND . . . . . . . . . . . . . . . . . . . –0.5 V dc to +7.0 V dc

AGND to DGND . . . . . . . . . . . . . . . . –0.5 V dc to +0.5 V dc

to AGND . . . . . . . . . . . . . . . . . . . +0.5 V dc to –7.0 V dc

V

EE

, VRT or VRB to AGND . . . . . . . . . . . . . . . . . +0.5 V to V

V

IN

EE

VRT to VRB . . . . . . . . . . . . . . . . . . . . . . –2.2 V dc to +2.2 V dc

CONV, NMINV or NLINV to DGND –0.5 V dc to +5.5 V dc
Applied Output Voltage to DGND . . . –0.5 V dc to +5.5 V dc
Applied Output Current, Externally Forced

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . –1.0 mA to +6.0 mA

2

3, 4

Output Short-Circuit Duration . . . . . . . . . . . . . . . . . . 1.0 sec

Operating Temperature Range (Ambient)

AD9048JJ/KJ/JQ/KQ . . . . . . . . . . . . . . . . . . . 0°C to +70°C

AD9048SE/SQ/TE/TQ . . . . . . . . . . . . . . –55°C to +125°C

Maximum Junction Temperature (Plastic) . . . . . . . . +150°C

Maximum Junction Temperature (Hermetic) . . . . . . +175°C

Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . .+300°C

Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C

5

6

6

ELECTRICAL CHARACTERISTICS

Parameter (Conditions) Temp Level Min Typ Max Min Typ Max Min Typ Max Min Typ Max Units

RESOLUTION 8 8 8 8 Bits

DC ACCURACY

Differential Nonlinearity +25°C I 0.4 0.75 0.3 0.5 0.4 0.75 0.3 0.5 LSB
Integral Nonlinearity +25°C I 0.6 0.75 0.4 0.5 0.6 0.75 0.4 0.5 LSB

No Missing Codes Full VI GUARANTEED GUARANTEED GUARANTEED GUARANTEED

INITIAL OFFSET ERROR

Top of Reference Ladder +25°CI 512 512 512 512mV
Bottom of Reference Ladder +25°CI 48 48 48 48 mV
Offset Drift Coefficient Full V 20 20 20 20 µV/°C

ANALOG INPUT

Input Voltage Range Full V –2.1; –2.1; –2.1; –2.1;

Input Bias Current

Input Resistance +25°C I 200 300 200 300 200 300 200 300 kΩ
Input Capacitance +25°CIV 1620 1620 1620 1620 pF

Full Power Bandwidth

REFERENCE INPUT

Positive Reference Voltage
Negative Reference Voltage
Differential Reference Voltage Full V 2.0 2.0 2.0 2.0 V

Reference Ladder Resistance Full VI 30 60 125 30 60 125 30 60 125 30 60 125 Ω
Ladder Temperature Coefficient Full V 0.22 0.22 0.22 0.22 Ω/°C

Reference Ladder Current Full VI 23 40 23 40 23 40 23 40 mA

Reference Input Bandwidth +25°C V 10 10 10 10 MHz

DYNAMIC PERFORMANCE

Conversion Rate +25°C I 35 38 35 38 35 38 35 38 MHz
Aperture Delay +25°C IV 2.4 5 2.4 5 2.4 5 2.4 5 ns
Aperture Uncertainty (Jitter) +25°CIV 2550 2550 2550 2550 ps

Output Delay (t
Output Hold Time (tOH)
Transient Response
Overvoltage Recovery Time

Rise Time +25°CI 9 9 9 9 ns
Fall Time +25°C I 14 14 14 14 ns

Output Time Skew

NMINV and NLINV INPUTS

+0.4 V Input Current Full VI 200 200 200 200 µA
+2.4 V Input Current Full VI 150 150 150 150 µA
+5.5 V Input Current Full VI 150 150 150 150 µA

CONVERT INPUT

Logic “1” Voltage Full VI 2.0 2.0 2.0 2.0 V
Logic “0” Voltage Full VI 0.8 0.8 0.8 0.8 V

Logic “1” Current Full VI 150 150 150 150 µA
Logic “0” Current Full VI 500 500 500 500 µA
Input Capacitance +25°CIV4646 4646pF
Convert Pulsewidth (LOW) +25°C I 18 18 18 18 ns
Convert Pulsewidth (HIGH) +25°C I 10 10 10 10 ns

7

8

9

) +25°C I 13 15 9 15 9 15 9 15 ns

PD

11

12

14

Full VI 1.0 0.75 1.0 0.75 LSB

Full VI 1.0 0.75 1.0 0.75 LSB

Full VI 12 12 12 12 mV

Full VI 8 8 8 8 mV

+25°C I 36 60 36 60 36 60 36 60 µA
Full VI 100 100 100 100 µA

Full VI 40 40 40 40 kΩ
+25°CIV1015101510151015MHz

Full V 0.0 0.0 0.0 0.0 V

9

Full V –2.0 –2.0 –2.0 –2.0 V

10

+25°CI 58 58 58 58 ns
+25°C IV 6 20 6 20 6 20 6 20 ns

13

+25°CV88 88ns

+25°C I 4.5 7 4.5 7 4.5 7 4.5 7 ns

(VCC = +5.0 V; VEE = –5.2 V; Differential Reference Voltage = 2.0 V, unless otherwise noted)

Test AD9048JJ/JQ AD9048KJ/KQ AD9048SE/SQ AD9048TE/TQ

+0.1 +0.1 +0.1 +0.1 V

REV. C–2–

AD9048

Parameter (Conditions) Temp Level Min Typ Max Min Typ Max Min Typ Max Min Typ Max Units

Test AD9048JJ/JQ AD9048KJ/KQ AD9048SE/SQ AD9048TE/TQ

AC LINEARITY

In-Band Harmonics

dc to 2.438 MHz
dc to 9.35 MHz

Signal-to-Noise Ratio (SNR)

1.248 MHz Input Frequency

2.438 MHz Input Frequency

1.248 MHz Input Frequency

2.438 MHz Input Frequency

Signal-to-Noise Ratio (SNR)

1.248 MHz Input Frequency

9.35 MHz Input Frequency
Noise Power Ratio (NPR)
Differential Phase
Differential Gain

15

16

15

16

17

19

20

20

+25°C I 47 50 49 55 47 50 49 55 dBc
+25°C V 48 48 48 48 dBc

17

+25°C I 43.5 44 45 46 43.5 44 45 46 dB

17

+25°C I 43 44 44 46 43 44 44 46 dB

18

+25°C I 52.5 53 54 55 52.5 53 54 55 dB

18

+25°C I 52 53 53 55 52 53 53 55 dB

17

+25°C I 43.5 44 45 46 43.5 44 45 46 dB
+25°C V 40.5 40.5 40.5 40.5 dB
+25°C IV 36.5 39 36.5 39 36.5 39 36.5 39 dB
+25°C IV 1 1 1 1 Degree
+25°CIV 2 2 2 2 %

DIGITAL OUTPUTS

Logic “1” Voltage Full VI 2.4 2.4 2.4 2.4 V
Logic “0” Voltage Full VI 0.5 0.5 0.5 0.5 V
Short Circuit Current

5

Full VI 30 30 30 30 mA

POWER SUPPLY

Positive Supply Current +25°C I 34 56 34 56 34 56 34 56 mA

Full VI 58 58 58 58 mA

Negative Supply Current +25°C I 90 110 90 110 90 110 90 110 mA

Full VI 120 120 120 120 mA

Nominal Power Dissipation +25°C V 550 550 550 550 mW
Reference Ladder Dissipation +25°C V 45 45 45 45 mW

NOTES

1

Maximum ratings are limiting values to be applied individually, and beyond which
the serviceability of the device may be impaired. Functional operation under any of
these conditions is not necessarily implied. Exposure to absolute maximum rating
conditions for extended periods of time may affect device reliability.

2

Applied voltage must be current-limited to specified range.

3

Forcing voltage must be limited to specified range.

4

Current is specified as negative when flowing into the device.

5

Output High; one pin to ground; one second duration.

6

Typical thermal impedances (no air flow) are as follows:

Ceramic DIP: θJA = 49°C/W; θJC = 15°C/W LCC: θJA = 69°C/W; θ
JLCC: θJA = 59°C/W; θJC = 19°C/W

= 21°C/W

JC

To calculate junction temperature (TJ), use power dissipation (PD) and thermal
impedance: T

7

Measured with VIN = 0 V and CONVERT low (sampling mode).

8

Determined by beat frequency testing for no missing codes.

9

V

≥ V

RT

= PD (θ

J

under all circumstances.

RB

) + T

JA

AMBIENT

= PD (θ

) = + T

JC

CASE.

10

Outputs terminated with 40 pF and eight 10 Ω pull-up resistors.

11

Interval from 50% point of leading edge CONVERT pulse to change in output
data.

12

For full-scale step input, 8-bit accuracy attained in specified time.

13

Recovers to 8-bit accuracy in specified time after –3 V input overvoltage.

14

Output time skew includes high-to-low and low-to-high transitions as well as
bit-to-bit time skew differences.

15

Measured at 20 MHz encode rate with analog input 1 dB below full scale.

16

Measured at 35 MHz encode rate with analog input 1 dB below full scale.

17

RMS signal to rms noise.

18

Peak signal to rms noise.

19

DC to 8 MHz noise bandwidth with 1.248 MHz slot; four sigma loading;
20 MHz encode.

20

Clock frequency = 4 × NTSC = 14.32 MHz. Measured with 40-IRE

modulated ramp.

Specifications subject to change without notice.

EXPLANATION OF TEST LEVELS

Test Level I – 100% production tested.

Test Level II – 100% production tested at +25°C and

sample tested at specific temperatures.
Test Level III – Sample tested only.
Test Level IV – Parameter is guaranteed by design and

characterization testing.

REV. C

Test Level V – Parameter is a typical value only.
Test Level VI – All devices are 100% production tested at

+25°C. 100% production tested at tempera-

ture extremes for military temperature de­vices; sample tested at temperature extremes
for commercial/industrial devices.

–3–

AD9048

28 271

2

3426

25

21

22

23

24

19

20

5
6
7
8

9
10
11

12

13 14 15 16 17 18

TOP VIEW

(Not to Scale)

NC = NO CONNECT

AGND
NC
V

IN

NC
NC
NC
AGND

DGND

V

CC

V

EE

V

EE

V

EE

V

CC

DGND

D4

D3D2D1 (MSB)

NLINV

D5D6D7

(LSB) D8

CONVERT

R

T

NMINV

R

M

R

B

AD9048

115106789

1921 2025 24 2223

18
17
16
15
14
13
12

TOP VIEW

(Not to Scale)

TOP VIEW

(Not to Scale)

26

28

27

1
2
3
4

CONVERT
D8 (LSB)
D7
D6
D5
NLINV

R

B

R

M

NMINV

(MSB) D1

D2
D3
D4

AGND

NC

V

IN

NC

NC

AGND

DGND

V

CC

VEEVEEV

EE

V

CC

DGND

NC = NO CONNECT

R

T

NC

AD9048

WARNING!

ESD SENSITIVE DEVICE

ORDERING GUIDE

Package

Model Linearity Temperature Option

1

AD9048JJ 0.75 LSB 0°C to +70°C J-28A
AD9048KJ 0.5 LSB 0°C to +70°C J-28A
AD9048JQ 0.75 LSB 0°C to +70°CQ-28
AD9048KQ 0.5 LSB 0°C to +70°CQ-28

AD9048SE
AD9048TE
AD9048SQ
AD9048TQ

NOTES

1

E = Leadless Ceramic Chip Carrier; J = J-Leaded Ceramic; Q = Cerdip.

2

For temperature designation only. MIL-STD-883 and Standard Military
Drawing available.

2

0.75 LSB –55°C to +125°C E-28A

2

0.5 LSB –55°C to +125°C E-28A

2

0.75 LSB –55°C to +125°CQ-28

2

0.5 LSB –55°C to +125°CQ-28

MECHANICAL INFORMATION

Die Dimensions . . . . . . . . . . . . . . . . 140 × 137 × 21 (±2) mils

Pad Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 × 4 mils

Metalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gold

Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . None

Substrate Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

EE

Passivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nitride

Die Attach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gold Eutectic

Bond Wire . . . . . . . . . . . . . . . .1 mil Gold; Gold Ball Bonding

PIN DESIGNATIONS

DIP (Q Package)

(MSB) D1

1

D2

2

D3

3

D4

4

DGND

5
6

V

CC

7

V

EE

8

V

EE

9

V

EE

V

10

CC

DGND

11

NLINV

12

D5

13

D6

14

NC = NO CONNECT

AD9048

TOP VIEW

(Not to Scale)

28
27
26
25
24
23
22
21
20
19
18
17
16
15

LCC (E Package)

NMINV
R

M

R

B

AGND
NC
V

IN

NC
NC
NC
AGND
R

T

CONVERT
D8 (LSB)
D7

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 the AD9048 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.

AGND AIN AGND

RLOW

RMID

NMINV

MSB

D2

D3

D4

DGND

VCCV

CCVEEVEEVEEVCCVCC

Bonding Diagram

DGND

RTOP

CONV

D8

D7

D6

D5

NLINV

DGND

–4–

J-Leaded Ceramic (J Package)

REV. C

PIN FUNCTION DESCRIPTIONS

AD9048

Pin Description

D1–D8 Eight digital outputs. D1 (MSB) is the most

significant bit of the digital output word;
D8 (LSB) is the least significant bit.

AGND One of two analog ground returns. Both

grounds should be connected together and to
low impedance ground plane near the AD9048.

DGND One of two digital ground returns. Both

grounds should be connected together and to
low impedance ground plane near the AD9048.

V

CC

V

EE

Positive supply terminals; nominally +5.0 V.

Negative supply terminals; nominally –5.2 V.

CONVERT Input for conversion signal; sample of analog

input signal taken on rising edge of this pulse.

Pin Description

R

B

Most negative reference voltage for internal
reference ladder.

R

M

R

T

Midpoint tap on internal reference ladder.

Most positive reference voltage for internal
reference ladder.

V

IN

Analog input signal pin.

NMINV “Not Most Significant Bit Invert.” In normal

operation, this pin floats high; logic LOW at
NMINV inverts most significant bit of digital
output word [D1 (MSB)].

NLINV “Not Least Significant Bit Invert.” In normal

operation, this pin floats high; logic LOW at
NLINV inverts the seven least significant bits
of the digital output word.

Burn-In Diagram

–5–REV. C

AD9048

THEORY OF OPERATION

Refer to the Functional Block Diagram of the AD9048. The
AD9048 comprises three functional sections: a comparator
array, encoding logic and output latches.

Within the array, the analog input signal to be digitized is com­pared with 255 reference voltages. The outputs of all compara­tors whose references are below the input signal level will be
high; outputs whose references are above that level will be low.

The n-of-255 code that results from this comparison is applied
to the encoding logic where it is converted into binary coding.
When it is inverted with dc signals applied to the NLINV and/or
NMINV pins, it becomes twos complement.

After encoding, the signal is applied to the output latch circuits
where it is held constant between updates controlled by the
application of CONVERT pulses.

The AD9048 uses strobed latching comparators in which com­parator outputs are either high or low, as dictated by the analog
input level. Data appearing at the output pins have a pipeline
delay of one encode cycle.

Input signal levels between the references applied to R

(Pin 26) will appear at the output as binary numbers

and R

B

(Pin 18)

T

between 0 and 255, inclusive. Signals outside that range will
show up as either full-scale positive or full-scale negative out­puts. No damage will occur to the AD9048 as long as the input
is within the voltage range of V

to +0.5 V.

EE

The significantly reduced input capacitance of the AD9048
lowers the drive requirements of the input buffer/amplifier and
also induces much smaller phase shift in the analog input signal.

Applications that depend on controlled phase shift at the con­verter input can benefit from using the AD9048 because of its
inherently lower phase shift.

The CONVERT, analog input and digital output circuits are
shown in Figure 1.

System timing, which provides details on delays through the
AD9048 as well as the relationships of various timing events, is
shown in Figure 2.

Dynamic performance of the AD9048, i.e., typical signal-to­noise ratio, is illustrated in Figures 3 and 4.

Figure 1. Input/Output Circuits

Figure 2. Timing Diagram

–6–

REV. C

Figure 3. Dynamic Performance (20 MHz Encode Rate)

AD9048

Ceramic 0.1 µF decoupling capacitors should be placed as closely

as possible to the supply pins of the AD9048. For decoupling

low frequency signals, use 10 µF tantalum capacitors, also con-

nected as closely as practical to voltage supply pins.

Within the AD9048, reference currents may vary because of
coupling between the clock and input signals. As a result, it is
important that the ends of the reference ladder, R

(Pin 28), be connected to low impedances (as measured

R

B

from ground).

If the AD9048 is being used in a circuit in which the reference
is not varied, a bypass capacitor to ground is strongly recom­mended. In applications that use varying references, they must
be driven from a low impedance source.

(Pin 18) and

T

Figure 4. Dynamic Performance (35 MHz Encode Rate)

LAYOUT SUGGESTIONS

Designs that use the AD9048 or any other high speed device
must follow some basic layout rules to ensure optimum
performance.

The first requirement is to have a large, low impedance ground
plane under and around the converter. If the system uses sepa­rate analog and digital grounds, both should be solidly con­nected together, and to the ground plane, as closely to the
AD9048 as practical to avoid ground loop currents.

Figure 5. Typical Connections

–7–REV. C

AD9048

1

28

5

11

12

18

26

BOTTOM

VIEW

19

4

25

0.028 (0.71)

0.022 (0.56)

0.050 ±0.005
(1.27 ±0.13)

0.040 (1.02) x 45°

REF 3 PLCS

0.055 (1.40)

0.045 (1.14)

0.075 (1.91) REF

NO 1
PIN INDEX

0.020 (0.51) x 45°

REF 1 PLC

1

0.458 (11.63)

0.442 (11.23)
SQ

0.100 (2.54)

0.064 (1.63)

NOTES

1

THIS DIMENSION CONTROLS THE OVERALL PACKAGE THICKNESS

2

APPLIES TO ALL FOUR SIDES

ALL TERMINALS ARE GOLD PLATED

Table I. Truth Table

Offset Twos

Binary

Step Range True Inverted True Inverted

–2.000 V FS –2.0480 V FS NMINV = 1 0 0 1

7.8431 mV Step 8.000 mV Step NLINV = 1 0 1 0
000 0.0000 V 0.0000 V 00000000 11111111 10000000 01111111
001 –0.0078 V –0.0080 V 00000001 11111110 10000001 01111110

•• • • • • •

•• • • • • •

•• • • • • •
127 –0.9961 V –1.0160 V 01111111 10000000 11111111 00000000
128 –1.0039 V –1.0240 V 10000000 01111111 00000000 11111111
129 –1.0118 V –1.0320 V 10000001 01111110 00000001 11111110

•• • • • • •

•• • • • • •

•• • • • • •
254 –1.9921 V –2.0320 V 11111110 00000001 01111110 10000001
255 –2.0000 V –2.0400 V 11111111 00000000 01111111 10000000

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

Complement

C1212a–0–1/99

28-Lead Ceramic Side-Brazed DIP

28

PIN 1

0.225 (5.72)

0.175 (4.45)

0.125 (3.18)

114

1.418 (36.02)

1.38 (35.06)

MAX

0.065 (1.66)

0.038 (0.965)

LEADS ARE GOLD PLATED (50 MICROINCHES MIN) KOVAR OR ALLOY 42

0.023 (0.508)

0.014 (0.381)

LEAD NO. 1 IDENTIFIED BY DOT OR NOTCH

0.105 (2.67)

0.095 (2.42)

BOTTOM VIEW

0.022 ±0.003

(0.559 ±0.076)

15

0.610 (15.24)

0.500 (14.43)

SEATING
PLANE

0.12 (3.05)

0.06 (1.53)

0.050
(1.27)

BSC

0.015 (0.305)

0.008 (0.203)

0.620 (15.4)

0.590 (14.74)

28-Lead J-Lead Package

0.450 ±0.006

(11.43 ±0.152)

25 19

26

PIN 1

4

5

0.488 ±0.010

(11.43 ±0.254)

TOP VIEW

(PINS DOWN)

SQ

SQ

–8–

11

28-Terminal Leadless Chip Carrier

0.171 (4.34)

18

12

0.300
(7.62)

TYP

MAX

0.102 ±0.010

(1.448 ±0.254)

0.039 ±0.005
(0.991 ±0.127)

0.028 ±0.002
(0.711 ±0.051)

0.420 ±0.010

(10.668 ±0.254)

0.019 ±0.002
(0.483 ±0.051)

0.006 ±0.0006
(0.152 ±0.015)

PRINTED IN U.S.A.

REV. C