Datasheet AD9216 Datasheet (Analog Devices)

Page 1
10-Bit, 105 MSPS

FEATURES

Integrated dual 10-bit ADC Single 3 V supply operation (2.85 V to 3.15 V) SNR = 57 dBc (to Nyquist, AD9216-105) SFDR = 75 dBc (to Nyquist, AD9216-105) Low power: 300 mW at 105 MSPS Differential input with 300 MHz 3 dB bandwidth Exceptional crosstalk immunity > 80 dB Offset binary or twos complement data format Clock duty cycle stabilizer

APPLICATIONS

Ultrasound equipment IF sampling in communications receivers
3G, radio point-to-point, LMDS, MMDS Battery-powered instruments Hand-held scopemeters Low cost digital oscilloscopes

GENERAL DESCRIPTION

The AD9216 is a dual, 3 V, 10-bit, 105 MSPS analog-to-digital converter (ADC). It features dual high performance sample-and hold amplifiers (SHAs) and an integrated voltage reference. The AD9216 uses a multistage differential pipelined architecture with output error correction logic to provide 10-bit accuracy and guarantee no missing codes over the full operating temperature range at up to 105 MSPS data rates. The wide bandwidth, differential SHA allows for a variety of user­selectable input ranges and offsets, including single-ended applications. The AD9216 is suitable for various applications, including multiplexed systems that switch full-scale voltage levels in successive channels and for sampling inputs at frequencies well beyond the Nyquist rate.
Dual A/D Converter
AD9216

FUNCTIONAL BLOCK DIAGRAM

AVDD AGND
VIN+_A
VIN–_A
REFT_A
REFB_A
VREF
SENSE
AGND
REFT_B
REFB_B
VIN+_B
VIN–_B
SHA
0.5V
SHA
AD9216
ADC
ADC
DRVDD
Figure 1.
10
OUTPUT
BUFFERS
CLOCK
DUTY CYCLE
STABILIZER
CONTROL
10
OUTPUT
BUFFERS
DRGND
Fabricated on an advanced CMOS process, the AD9216 is available in a space saving, Pb-free, 64-lead LFCSP (9 mm × 9 mm) and is specified over the industrial temperature range (−40°C to +85°C).

PRODUCT HIGHLIGHTS

1. Pin compatible with AD9238, dual 12-bit 20 MSPS/40 MSPS/
65 MSPS ADC and AD9248, dual 14-bit 20 MSPS/40 MSPS/ 65 MSPS ADC.
2. 105 MSPS capability allows for demanding high frequency
applications.
MUX/
MODE
MUX/
10
10
D9_A–D0_A OEB_A
MUX_SELECT CLK_A CLK_B DCS
SHARED_REF PWDN_A PWDN_B DFS
D9_B–D0_B OEB_B
04775-001
Dual single-ended clock inputs are used to control all internal conversion cycles. A duty cycle stabilizer is available on the AD9216 and can compensate for wide variations in the clock duty cycle, allowing the converters to maintain excellent performance. The digital output data is presented in either straight binary or twos complement format.
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.
3. Low power consumption: AD9216-105: 105 MSPS = 300 mW.
4. The patented SHA input maintains excellent performance for
input frequencies up to 200 MHz and can be configured for single-ended or differential operation.
5. Typical channel crosstalk of > 80 dB @ f
up to 70 MHz.
IN
6. The clock duty cycle stabilizer maintains performance over a
wide range of clock duty cycles.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
www.analog.com
Page 2
AD9216

TABLE OF CONTENTS

DC Specifications ............................................................................. 3
Output Coding............................................................................ 22
AC Specifications.............................................................................. 4
Logic Specifications.......................................................................... 6
Switching Specifications .................................................................. 7
Timing Diagram ............................................................................... 8
Absolute Maximum Ratings............................................................ 9
Explanation of Test Levels........................................................... 9
ESD Caution.................................................................................. 9
Pin Configuration and Function Descriptions........................... 10
Te r m in o l o g y .................................................................................... 12
Typical Performance Characteristics........................................... 14
Equivalent Circuits......................................................................... 18
Theory of Operation ...................................................................... 19
Analog Input ............................................................................... 19
Clock Input and Considerations ..............................................20
Power Dissipation and Standby Mode..................................... 21
Timing ......................................................................................... 22
Data Format................................................................................ 22
Voltage Reference....................................................................... 23
Dual ADC LFCSP PCB.................................................................. 25
Power Connector ........................................................................ 25
Analog Inputs.............................................................................. 25
Optional Operational Amplifier............................................... 25
Clock ............................................................................................ 25
Volt a ge R e fer e nce ....................................................................... 25
Data Outputs............................................................................... 25
LFCSP Evaluation Board Bill of Materials (BOM) ................ 26
LFCSP PCB Schematics............................................................. 27
LFCSP PCB Layers..................................................................... 30
Thermal Considerations............................................................ 35
Outline Dimensions....................................................................... 36
Digital Outputs ...........................................................................21
REVISION HISTORY
10/04—Revision 0: Initial Version
Ordering Guide .......................................................................... 36
Rev. 0 | Page 2 of 36
Page 3
AD9216

DC SPECIFICATIONS

AVDD = 3.0 V, DRVDD = 3.0 V, maximum sample rate, CLK_A = CLK_B; AIN = −0.5 dBFS differential input, 1.0 V internal reference,
to T
T
MIN
Table 1.
Parameter Temp Test Level Min Typ Max Unit RESOLUTION Full VI 10 Bits ACCURACY
No Missing Codes Full VI Guaranteed
Offset Error Full VI −3.6 ±0.7 +3.6 % FSR
Gain Error
Differential Nonlinearity (DNL)
25°C I −0.65 ±0.5 +1.0 LSB
Integral Nonlinearity (INL)2 Full V −2.8 ±1.0 +2.8 LSB 25°C I −1.8 ±1.0 +1.8 LSB TEMPERATURE DRIFT
Offset Error Full V ±10 µV/°C
Gain Error1 Full V ±75 ppm/°C
Reference Voltage Full V ±15 ppm/°C INTERNAL VOLTAGE REFERENCE
Output Voltage Error Full VI ±2 ±35 mV
Load Regulation @ 1.0 mA 25°C V 1.0 mV INPUT REFERRED NOISE
Input Span = 2.0 V 25°C V 0.5 LSB rms ANALOG INPUT
Input Span, VREF = 1.0 V Full IV 2 V p-p
Input Capacitance REFERENCE INPUT RESISTANCE Full V 7 kΩ POWER SUPPLIES
Supply Voltages
Supply Current
PSRR Full V ±0.1 % FSR POWER CONSUMPTION
P
AVDD
P
DRVDD
Standby Power MATCHING CHARACTERISTICS
Offset Matching Error
Gain Matching Error (Shared Reference Mode) 25°C I −0.6 ±0.1 +0.6 % FSR
Gain Matching Error (Nonshared Reference Mode) 25°C I −1.6 ±0.3 +1.6 % FSR
1
Gain error and gain temperature coefficient are based on the ADC only (with a fixed 1.0 V external reference).
2
Measured with low frequency ramp at maximum clock rate.
3
Input capacitance refers to the effective capacitance between one differential input pin and AVSS. Refer to Figure for the equivalent analog input structure. 24
4
Measured with low frequency analog input at maximum clock rate with approximately 5 pF loading on each output bit.
5
Standby power is measured with the CLK_A and CLK_B pins inactive (i.e., set to AVDD or AGND).
6
Shared reference mode or nonshared reference mode.
, DCS enabled, unless otherwise noted.
MAX
AD9216BCPZ-105
1
2
3
25°C VI −1.6 ±0.7 +1.6 % FSR Full V −1.0 ±0.5 +1.66 LSB
Full V 2 pF
AVDD Full IV 2.85 3.0 3.15 V DRVDD Full IV 2.85 3.0 3.15 V
4
IAVDD
Full VI 100 110 mA
IDRVDD4 Full VI 24 mA
4
4
5
6
25°C I 300 330 mW 25°C V 72 mW 25°C V 3.0 mW
25°C I −6.0 ±1.0 +6.0 % FSR
Rev. 0 | Page 3 of 36
Page 4
AD9216

AC SPECIFICATIONS

AVDD = 3.0 V, DRVDD = 3.0 V, maximum sample rate, CLK_A = CLK_B; AIN = −0.5 dBFS differential input, 1.0 V internal reference,
to T
T
MIN
Table 2.
Parameter Temp Test Level Min Typ Max Unit SIGNAL-TO-NOISE RATIO (SNR)
f
INPUT
25°C I 56.6 57.8 dB f
INPUT
25°C I 56.4 57.6 dB f
INPUT
f
INPUT
SIGNAL-TO-NOISE AND DISTORTION RATIO (SINAD)
f
INPUT
25°C I 56.5 57.7 dB f
INPUT
25°C I 56.1 57.4 dB f
INPUT
f
INPUT
EFFECTIVE NUMBER OF BITS (ENOB)
f
INPUT
25°C I 9.2 9.4 Bits f
INPUT
25°C I 9.1 9.3 Bits f
INPUT
f
INPUT
WORST HARMONIC (SECOND OR THIRD)
f
INPUT
25°C I −76.0 −68.0 dBc f
INPUT
25°C I −74.0 −65.0 dBc f
INPUT
f
INPUT
WORST OTHER (EXCLUDING SECOND OR THIRD) f
INPUT
25°C I −75.0 −66.0 dBc f
INPUT
25°C I −75.0 −63.0 dBc f
INPUT
f
INPUT
SPURIOUS-FREE DYNAMIC RANGE (SFDR)
f
INPUT
25°C I 66.0 75.0 dBc f
INPUT
25°C I 63.0 74.0 dBc f
INPUT
f
INPUT
, DCS enabled, unless otherwise noted.
MAX
AD9216BCPZ-105
= 2.4 MHz Full IV 55.0 57.8 dB
= 50 MHz Full IV 54.8 57.6 dB
= 69 MHz 25°C V 57.4 dB = 100 MHz 25°C V 57.3 dB
= 2.4 MHz Full IV 54.9 57.7 dB
= 50 MHz Full IV 54.3 57.4 dB
= 69 MHz 25°C V 56.8 dB = 100 MHz 25°C V 56.7 dB
= 2.4 MHz Full IV 8.9 9.4 Bits
= 50 MHz Full IV 8.8 9.3 Bits
= 69 MHz 25°C V 9.2 Bits = 100 MHz 25°C V 9.2 Bits
= 2.4 MHz Full IV −76.0 −64.6 dBc
= 50 MHz Full IV −74.0 −58.4 dBc
= 69 MHz 25°C V −74.0 dBc = 100 MHz 25°C V −74.0 dBc
= 2.4 MHz Full IV −75.0 −65.0 dBc
= 50 MHz Full IV −75.0 −62.0 dBc
= 69 MHz 25°C V −77.0 dBc = 100 MHz 25°C V −77.0 dBc
= 2.4 MHz Full IV 64.6 75.0 dBc
= 50 MHz Full IV 58.4 74.0 dBc
= 69 MHz 25°C V 74.0 dBc = 100 MHz 25°C V 74.0 dBc
Rev. 0 | Page 4 of 36
Page 5
AD9216
AD9216BCPZ-105
Parameter Temp Test Level Min Typ Max Unit
TWO-TONE SFDR (AIN = −7 dBFS)
f
= 69.1 MHz, f
IN1
f
= 100.1 MHz, f
IN1
= 70.1 MHz 25°C V 70 dBc
IN2
= 101.1 MHz 25°C V 69 dBc
IN2
ANALOG BANDWIDTH 25°C V 300 MHz CROSSTALK 25°C V −80.0 dB
Rev. 0 | Page 5 of 36
Page 6
AD9216

LOGIC SPECIFICATIONS

AVDD = 3.0 V, DRVDD = 3.0 V, maximum sample rate, CLK_A = CLK_B; AIN = −0.5 dBFS differential input, 1.0 V internal reference,
to T
T
MIN
Table 3.
Parameter Temp Test Level Min Typ Max Unit LOGIC INPUTS
High Level Input Voltage Full IV 2.0 V Low Level Input Voltage Full IV 0.8 V High Level Input Current Full IV −10 +10 µA Low Level Input Current Full IV −10 +10 µA Input Capacitance Full IV 2 pF
LOGIC OUTPUTS
DRVDD = 3.0 V
1
Output voltage levels measured with 5 pF load on each output.
, DCS enabled, unless otherwise noted.
MAX
AD9216BCPZ-105
1
High Level Output Voltage Full IV 2.95 V Low Level Output Voltage Full IV 0.05 V
Rev. 0 | Page 6 of 36
Page 7
AD9216

SWITCHING SPECIFICATIONS

AVDD = 3.0 V, DRVDD = 3.0 V, maximum sample rate, CLK_A = CLK_B; AIN = −0.5 dBFS differential input, 1.0 V internal reference,
to T
T
MIN
Table 4.
Parameter Temp Test Level Min Typ Max Unit SWITCHING PERFORMANCE
Maximum Conversion Rate Full VI 105 MSPS
Minimum Conversion Rate Full V 10 MSPS
CLK Period Full V 9.5 ns OUTPUT PARAMETERS
Output Propagation Delay2 (tPD) 25°C I 3.75 4.6 ns
Valid Time3 (tV) 25°C I 2.0
Output Rise Time (10% to 90%) 25°C V 1.0 ns
Output Fall Time (10% to 90%) 25°C V 1.0 ns
Output Enable Time
Output Disable Time4 25°C V 1 Cycle
Pipeline Delay (Latency) Full V 6 Cycles APERTURE
Aperture Delay (tA) Full V 1.5 ns
Aperture Uncertainty (tJ) Full V 0.5 ps rms
Wake-Up Time OUT-OF-RANGE RECOVERY TIME Full V 1 Cycle
1
C
LOAD
2
Output delay is measured from clock 50% transition to data 50% transition.
3
Valid time is approximately equal to the minimum output propagation delay.
4
Output enable time is OEB_A, OEB_B falling to respective channel outputs coming out of high impedance. Output disable time is OEB_A, OEB_B rising to respective
channel outputs going into high impedance.
5
Wake-up time is dependent on value of decoupling capacitors; typical values shown for 0.1 µF and 10 µF capacitors on REFT and REFB.
, DCS enabled, unless otherwise noted.
MAX
1
4
5
equals 5 pF maximum for all output switching parameters.
AD9216BCPZ-105
25°C V 1 Cycle
Full V 7 ms
Rev. 0 | Page 7 of 36
Page 8
AD9216

TIMING DIAGRAM

ANALOG
INPUT
CLK
N–1
N+1
N
t
A
N+2
N+3
N+4
N+5
N+8
N+7
N+6
DATA
OUT
N–8 N–7 N–6 N–5 N–4 N–3 N–2 N–1 N N+1
t
PD
04775-002
Figure 2.
Rev. 0 | Page 8 of 36
Page 9
AD9216

ABSOLUTE MAXIMUM RATINGS

Table 5.
Parameter Rating Pin Name With Respect To Min Max Unit
ELECTRICAL
ENVIRONMENTAL
1
2
1
AVDD AGND −0.3 +3.9 V
DRVDD DRGND −0.3 +3.9 V
AGND DRGND −0.3 +0.3 V
AVDD DRVDD −3.9 +3.9 V
Digital Outputs CLK, DCS, MUX_SELECT, SHARED_REF DRGND −0.3 DRVDD + 0.3 V
OEB, DFS AGND −0.3 AVDD + 0.3 V
VINA, VINB AGND −0.3 AVDD + 0.3 V
VREF AGND −0.3 AVDD + 0.3 V
SENSE AGND −0.3 AVDD + 0.3 V
REFB, REFT AGND −0.3 AVDD + 0.3 V
PDWN AGND −0.3 AVDD + 0.3 V
2
Operating Temperature −45 +85 °C
Junction Temperature 150 °C
Lead Temperature (10 sec) 300 °C
Storage Temperature −65 +150 °C
Absolute maximum ratings are limiting values to be applied individually, and beyond which the serviceability of the circuit may be impaired. Functional operability is
not necessarily implied. Exposure to absolute maximum rating conditions for an extended period of time may affect device reliability.
Typical thermal impedances (64-lead LFCSP); θ
EIA/JESD51-7.
= 26.4°C/W. These measurements were taken on a 4-layer board (with thermal via array) in still air, in accordance with
JA

EXPLANATION OF TEST LEVELS

Table 6.
Test Level Description
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; guaranteed by design and characterization testing for industrial temperature range; 100% production tested at temperature extremes for military devices.

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 9 of 36
Page 10
AD9216
A

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

AVDD
CLK_A
SHARED_REF
MUX_SELECT
PDWN_A
OEB_A
DNC
D9_A (MSB)
D8_A
D7_A
D6_A
DRGND
DRVDD
D5_A
D4_A
AGND VIN+_A VIN–_A
AGND
AVDD REFT_A REFB_
VREF
SENSE REFB_B REFT_B
AVDD
AGND VIN–_B VIN+_B
AGND
646362616059585756555453525150
PIN 1
1
INDICATOR
2 3 4 5 6 7 8
9 10 11 12 13 14 15 16
AD9216
TOP VIEW
(Not to Scale)
D3_A 49
D2_A
48
D1_A
47
D0_A (LSB)
46
DNC
45
DNC
44
DNC
43
DNC
42
DRVDD
41
DRGND
40
DNC
39
D9_B (MSB)
38
D8_B
37
D7_B
36
D6_B
35
D5_B
34
D4_B
33
DNC = DO NOT CONNECT
171819202122232425262728293031
DFS
DCS
DNC
DNC
DNC
AVDD
CLK_B
PDWN_B
OEB_B
DNC
D0_B (LSB)
DRVDD
DRGND
D1_B
D2_B
32
D3_B
04775-003
Figure 3. Pin Configuration
Rev. 0 | Page 10 of 36
Page 11
AD9216
Table 7. Pin Function Descriptions
Pin No. Mnemonic Description
1, 4, 13, 16 AGND Analog Ground. 2 VIN+_A Analog Input Pin (+) for Channel A. 3 VIN−_A Analog Input Pin (−) for Channel A. 5, 12, 17, 64 AVDD Analog Power Supply. 6 REFT_A Differential Reference (+) for Channel A. 7 REFB_A Differential Reference (−) for Channel A. 8 VREF Voltage Reference Input/Output. 9 SENSE Reference Mode Selection. 10 REFB_B Differential Reference (−) for Channel B. 11 REFT_B Differential Reference (+) for Channel B. 14 VIN−_B Analog Input Pin (−) for Channel B. 15 VIN+_B Analog Input Pin (+) for Channel B. 18 CLK_B Clock Input Pin for Channel B. 19 DCS Duty Cycle Stabilizer (DCS) Mode Pin (Active High). 20 DFS Data Output Format Select Pin (Low for Offset Binary, High for Twos Complement). 21 PDWN_B Power-Down Function Selection for Channel B (Active High). 22 OEB_B
23 to 26, 39, 42 to 45, 58
27, 30 to 38
28, 40, 53 DRGND Digital Output Ground. 29, 41, 52 DRVDD
46 to 51, 54 to 57
59 OEB_A
60 PDWN_A Power-Down Function Selection for Channel A (Active High). 61 MUX_SELECT Data Multiplexed Mode. (See Data Format section for how to enable). 62 SHARED_REF Shared Reference Control Bit (Low for Independent Reference Mode, High for Shared Reference Mode). 63 CLK_A Clock Input Pin for Channel A.
DNC Do Not Connect Pins. Should be left floating.
D0_B (LSB) to D9_B (MSB)
D0_A (LSB) to D9_A (MSB)
Output Enable for Channel B (Low Setting Enables Channel B Output Data Bus). Outputs are high impedance when OEB_B is set high.
Channel B Data Output Bits.
Digital Output Driver Supply. Must be decoupled to DRGND with a minimum 0.1 µF capacitor. Recommended decoupling is 0.1 µF capacitor in parallel with 10 µF.
Channel A Data Output Bits.
Output Enable for Channel A (Low Setting Enables Channel A Output Data Bus). Outputs are high impedance when OEB_A is set high.
Rev. 0 | Page 11 of 36
Page 12
AD9216

TERMINOLOGY

Analog 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.
Aperture Delay
The delay between the 50% point of the rising edge of the encode command and the instant the analog input is sampled.
Aperture Uncertainty (Jitter)
The sample-to-sample variation in aperture delay.
Clock Pulse Width/Duty Cycle
Pulse-width high is the minimum amount of time that the clock pulse should be left in a Logic 1 state to achieve rated performance; pulse-width low is the minimum time clock pulse should be left in a low state. See timing implications of changing t At a given clock rate, these specifications define an acceptable clock duty cycle.
Crosstalk
Coupling onto one channel being driven by a low level (−40 dBFS) signal when the adjacent interfering channel is driven by a full-scale signal.
Differential Analog Input Resistance, Differential Analog Input Capacitance, and Differential Analog Input Impedance
The real and complex impedances measured at each analog input port. The resistance is measured statically and the capacitance and differential input impedances are measured with a network analyzer.
Differential Analog Input Voltage Range
The peak-to-peak differential voltage that must be applied to the converter to generate a full-scale response. Peak differential voltage is computed by observing the voltage on a single pin and subtracting the voltage from the other pin, which is 180° out of phase. Peak-to-peak differential is computed by rotating the inputs phase 180° and by taking the peak measurement again. The difference is then computed between both peak measurements.
Differential Nonlinearity
The deviation of any code width from an ideal 1 LSB step.
Effective Number of Bits (ENOB) The ENOB is calculated from the measured SINAD based on the equation (assuming full-scale input)
in the Clock Input and Considerations section.
EH
ENOB
SINAD
=
MEASURED
6.02
dB1.76
Full-Scale Input Power
Expressed in dBm and computed using the following equation.
2
V
FULLSCALE
Z
log10
Power
FULLSCALE
=
INPUT
0.001
⎜ ⎝
rms
⎞ ⎟
⎟ ⎟ ⎟
⎟ ⎠
Gain Error
The difference between the measured and ideal full-scale input voltage range of the ADC.
Harmonic Distortion, Second
The ratio of the rms signal amplitude to the rms value of the second harmonic component, reported in dBc.
Harmonic Distortion, Third
The ratio of the rms signal amplitude to the rms value of the third harmonic component, reported in dBc.
Integral Nonlinearity
The deviation of the transfer function from a reference line measured in fractions of 1 LSB using a best straight line determined by a least square curve fit.
Minimum Conversion Rate
The encode rate at which the SNR of the lowest analog signal frequency drops by no more than 3 dB below the guaranteed limit.
Maximum Conversion Rate
The encode rate at which parametric testing is performed.
Output Propagation Delay
The delay between a 50% crossing of the CLK rising edge and the time when all output data bits are within valid logic levels.
Noise (for Any Range within the ADC)
This value includes both thermal and quantization noise.
noise
ZV
××=
10.0010
⎜ ⎝
10
dBFSdBcdBm
⎟ ⎠
SignalSNRFS
where:
Z is the input impedance.
FS is the full scale of the device for the frequency in question.
SNR is the value for the particular input level.
is the signal level within the ADC reported in dB below
Signal
full scale.
Rev. 0 | Page 12 of 36
Page 13
AD9216
Power Supply Rejection Ratio
The specification shows the maximum 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 signal amplitude (set 1 dB below full scale) to the rms value of the sum of all other spectral components, including harmonics, but excluding dc.
Signal-to-Noise Ratio (without Harmonics)
The ratio of the rms signal amplitude (set at 1 dB below full scale) to the rms value of the sum of all other spectral components, excluding the first seven 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. It also may be reported in dBc (that is, degrades as signal level is lowered) or dBFS (that is, always related back to converter full scale).
Two-Tone Intermodulation Distortion Rejection
The ratio of the rms value of either input tone to the rms value of the worst third-order intermodulation product, in dBc.
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. It also may be reported in dBc (that is, degrades as signal level is lowered) or in dBFS (that is, always relates back to converter full scale).
Wors t Oth e r S p u r
The ratio of the rms signal amplitude to the rms value of the worst spurious component (excluding the second and third harmonic), reported in dBc.
Transient Response Time
The time it takes for the ADC to reacquire the analog input after a transient from 10% above negative full scale to 10% below positive full scale.
Out-of-Range Recovery Time
The time it takes for the ADC to reacquire the analog input after a transient 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.
Rev. 0 | Page 13 of 36
Page 14
AD9216

TYPICAL PERFORMANCE CHARACTERISTICS

AVDD, DRVDD = 3.0 V, T = 25°C, AIN differential drive, full scale = 2 V mode, internal reference, DCS on, unless otherwise noted.
0
–20
–40
–60
–80
AMPLITUDE (dBFS)
–100
–120
Figure 4. FFT: f
0
–20
–40
–60
–80
AMPLITUDE (dBFS)
–100
–120
Figure 5. FFT: f
0
–20
–40
–60
–80
AMPLITUDE (dBFS)
–100
SNR = 57.8dB SINAD = 57.8dB H2 = –92.7dBc H3 = –80.3dBc SFDR = 78.2dBc
20 30010 4050
FREQUENCY (MHz)
= 105 MSPS, AIN = 10.3 MHz @ −0.5 dBFS
S
SNR = 56.9dB SINAD = 56.8dB H2 = –78.5dBc H3 = –80dBc SFDR = 78.3dBc
20 30010 4050
FREQUENCY (MHz)
= 105 MSPS, AIN = 70 MHz @ −0.5 dBFS
S
SNR = 57.5dB SINAD = 57.3dB H2 = –74dBc H3 = –84.3dBc SFDR = 74dBc
04775-018
04775-019
0
–10
–20
–30
–40
–50
–60
AMPLITUDE (dBFS)
–70
–80
–90
–100
27 28 29
Figure 7. FFT: f
70MHz ON CHANNEL A ACTIVE
76MHz CROSSTALK FROM CHANNEL B
30 31 32 33 34 35
(76)
FREQUENCY (MHz)
= 105 MSPS, AIN =70 MHz, 76 MHz
S
(A Port FFT while Both A and B Ports Are Driven @ −0.5 dBFS)
100
H3
90
H2
80
dB
70
60
50
0 20 40 60 80 100 120
SNR
SINAD
CLOCK FREQUENCY (MHz)
SFDR
Figure 8. SNR, SINAD, H2, H3, SFDR vs.
Sample Clock Frequency, A
100
90
80
dB
70
60
= 70 MHz @ −0.5 dBFS
IN
H2
SFDR
H3
SNR
(70)
04775-021
36
04775-022
–120
Figure 6. FFT: f
20 30010 4050
FREQUENCY (MHz)
= 105 MSPS, AIN = 100 MHz @ −0.5 dBFS
S
04775-020
Rev. 0 | Page 14 of 36
50
0 50 100 150 200 250 300
ANALOG INPUT FREQUENCY (MHz)
Figure 9. Analog Inp ut Frequency Sweep, A
=−0.5 dBFS, fS = 105 MSPS
IN
SINAD
04775-023
Page 15
AD9216
80
70
60
50
dB
40
30
20
–50 –45 –40 –35 –30 –25 –20 –15 –10 –5 0
SFDR dBFS
SFDR dBc
AIN INPUT LEVEL (dBFS)
65dB REF LINE
Figure 10. SFDR vs. Analog Input Level,
= 70 MHz, fS = 105 MSPS
A
IN
0
–10
–20
–30
–40
–50
AMPLITUDE (dBFS)
–60
–70
–80
–90
–100
IMD = –69.9dBc
20 30010 4050
INPUT FREQUENCY (MHz)
Figure 11. Two-Tone IMD Performance,
F1, F2 = 69.1 MHz, 70.1 MHz @ −7 dBFS, 105 MSPS
90
80
70
60
50
dB
40
30
20
10
0
–60 –50 –40 –30 –20 –10 0
TWO-TONE SFDR dBFS
TWO-TONE SFDR dBc
70dB REF LINE
TWO-TONE ANALOG INPUT LEVEL (dBFS)
Figure 12. Two-Tone Intermodulation Distortion vs. Input Drive Level
(69.1 MHz and 70.1 MHz; f
= 105 MSPS; F1, F2 Levels Equal)
S
04775-024
04775-025
04775-026
100
90
80
70
TWO-TONE SFDR dBFS
60
50
dB
40
30
20
10
0
–60 –50 –40 –30 –20 –10 0
TWO-TONE SFDR dBc
70dB REF LINE
TWO-TONE ANALOG INPUT LEVEL (dBFS)
Figure 13. Two-Tone Intermodulation Distortion vs. Input Drive Level
(100.1 MHz and 101.1 MHz; f
100
90
80
70
60
50
40
CURRENT (mA)
30
20
10
0
0 20 40 60 80 100 120
SAMPLE CLOCK RATE (MSPS)
Figure 14. I
C
= 5 pF, AIN = 70 MHz @ −0.5 dBFS
LOAD
80
70
60
SNR DCS ON
50
dB
40
30
20
25 30 35 40 45 50 55 60 65 70 75
SNR DCS OFF
= 105 MSPS; F1, F2 Levels Equal)
S
AVDD CURRENT
DRVDD CURRENT
, I
AVDD
POSITIVE DUTY CYCLE (%)
vs. Clock Frequency,
DRVDD
SFDR DCS ON
SFDR DCS OFF
Figure 15. SNR, SFDR vs. Positive Duty Cycle DCS Enabled, Disabled;
= 70 MHz @ −0.5 dBFS, 105 MSPS
A
IN
04775-027
04775-028
04775-029
Rev. 0 | Page 15 of 36
Page 16
AD9216
80
80
75
70
65
60
dB
55
50
45
40
0.25 0.35 0.45 0.55 0.65 0.75 0.85 0.95 1.05 1.15 1.25
SFDR
SNR
VREF (V)
Figure 16. SNR, SFDR vs. External VREF (Full Scale = 2 × VREF)
= 70.3 MHz @ −0.5 dBFS, 105 MSPS
A
IN
1.0
0.8
0.6
0.4
0.2
EXTERNAL REFERENCE MODE
0
–0.2
–0.4
GAIN ERROR (% Full Scale)
–0.6
–0.8
–1.0
40–20020406080
INTERNAL REFERENCE MODE
TEMPERATURE (°C)
Figure 17. Typical Gain Error Variation vs. Temperature,
= 70 MHz @ 0.5 dBFS, 105 MSPS (Normalized to 25°C)
A
IN
80
04775-030
04775-031
75
70
dB
65
60
55
40–20020406080
SFDR
SNR
SINAD
TEMPERATURE (°C)
Figure 19. SNR, SINAD, SFDR vs. Temperature,
= 70 MHz @ −0.5 dBFS, 105 MSPS (fS = 2 V, External Reference Mode)
A
IN
80
SNR
SINAD
SFDR
2.92.8 3.0 3.1 3.2 AVDD (V)
= 70 MHz @ −0.5 dBFS, 105 MSPS
IN
75
70
dB
65
60
55
Figure 20. SNR, SINAD, SFDR vs. AVDD, A
2.0
04775-033
04775-034
75
70
dB
65
60
55
40–20020406080
SFDR
SNR
SINAD
TEMPERATURE (°C)
Figure 18. SNR, SINAD, SFDR vs. Temperature,
= 70 MHz @ −0.5 dBFS, 105 MSPS (fS = 2 V, Internal Reference Mode)
A
IN
04775-032
Rev. 0 | Page 16 of 36
1.5
1.0
0.5
0
LSB
–0.5
–1.0
–1.5
–2.0
0 200 400 600 800 1000
CODE
Figure 21. Typical DNL Plot, A
= 10.3 MHz @ −0.5 dBFS, 105 MSPS
IN
04775-035
Page 17
AD9216
2.0
1.5
1.0
0.5
0
LSB
–0.5
–1.0
–1.5
–2.0
0 200 400 600 800 1000
Figure 22. Typical INL Plot, A
CODE
= 10.3 MHz @ −0.5 dBFS, 105 MSPS
IN
04775-036
4.9
4.7
4.5
4.3
(ns)
PD
T
4.1
3.9
3.7
3.5 –20 0 20 40 80
–40 60
TEMPERATURE (°C)
Figure 23. Typical Propagation Delay vs. Temperature
04775-037
Rev. 0 | Page 17 of 36
Page 18
AD9216

EQUIVALENT CIRCUITS

AVDD
AVDD
VIN+_A, VIN–_A, VIN+_B, VIN–_B
CLK_A, CLK_B
DCS, DFS,
MUX_SELECT,
SHARED_REF
Figure 24. Equivalent Analog Input
AVDD
Figure 25. Equivalent Clock, Digital Inputs Circuit
04775-004
04775-005
PDWN
30k
04775-006
Figure 26. Power-Down Input
DRVDD
04775-007
Figure 27. Digital Outputs
Rev. 0 | Page 18 of 36
Page 19
AD9216

THEORY OF OPERATION

The AD9216 consists of two high performance ADCs that are based on the AD9215 converter core. The dual ADC paths are independent, except for a shared internal band gap reference source, VREF. Each of the ADC paths consists of a proprietary front end SHA followed by a pipelined switched-capacitor ADC. The pipelined ADC is divided into three sections, consisting of a sample-and-hold amplifier, followed by seven
1.5-bit stages, and a final 3-bit flash. Each stage provides sufficient overlap to correct for flash errors in the preceding stages. The quantized outputs from each stage are combined through the digital correction logic block into a final 10-bit result. The pipelined architecture permits the first stage to operate on a new input sample, while the remaining stages operate on preceding samples. Sampling occurs on the rising edge of the respective clock.
Each stage of the pipeline, excluding the last, consists of a low resolution flash ADC and a residual multiplier to drive the next stage of the pipeline. The residual multiplier uses the flash ADC output to control a switched capacitor digital-to-analog converter (DAC) of the same resolution. The DAC output is subtracted from the stage’s input signal and the residual is amplified (multiplied) to drive the next pipeline stage. The residual multiplier stage is also called a multiplying DAC (MDAC). One bit of redundancy is used in each one of the stages to facilitate digital correction of flash errors. The last stage simply consists of a flash ADC.
The input stage contains a differential SHA that can be configured as ac- or dc-coupled in differential or single­ended modes. The output-staging block aligns the data, carries out the error correction, and passes the data to the output buffers. The output buffers are powered from a separate supply, allowing adjustment of the output voltage swing.

ANALOG INPUT

The analog input to the AD9216 is a differential switched­capacitor SHA that has been designed for optimum performance while processing a differential input signal. The SHA input accepts inputs over a wide common-mode range. An input common-mode voltage of midsupply is recommended to maintain optimal performance.
input; therefore, the precise values are dependant on the application. In IF under-sampling applications, any shunt capacitors should be removed. In combination with the driving source impedance, they would limit the input bandwidth. For best dynamic performance, the source impedances driving VIN+ and VIN− should be matched such that common-mode settling errors are symmetrical. These errors are reduced by the common-mode rejection of the ADC.
H
VIN+
VIN
T
C
PAR
T
C
PAR
Figure 28. Switched-Capacitor Input
0.5pF
0.5pF
T
T
H
An internal differential reference buffer creates positive and negative reference voltages, REFT and REFB, respectively, that define the span of the ADC core. The output common-mode of the reference buffer is set to midsupply, and the REFT and REFB voltages and span are defined as:
REFT = 1/2 (AV D D + VREF)
REFB = 1/2 (AV D D VREF)
Span = 2 × (REFTREFB) = 2 × VREF
It can be seen from the equations above that the REFT and REFB voltages are symmetrical about the midsupply voltage and, by definition, the input span is twice the value of the VREF voltage.
The SHA may be driven from a source that keeps the signal peaks within the allowable range for the selected reference voltage. The minimum and maximum common-mode input levels are defined as
VCM
= VREF/2
MIN
04775-008
The SHA input is a differential switched-capacitor circuit. In Figure 28, the clock signal alternatively switches the SHA between sample mode and hold mode. When the SHA is switched into sample mode, the signal source must be capable of charging the sample capacitors and settling within one-half of a clock cycle. A small resistor in series with each input can help reduce the peak transient current required from the output stage of the driving source. Also, a small shunt capacitor can be placed across the inputs to provide dynamic charging currents. This passive network creates a low-pass filter at the ADC’s
Rev. 0 | Page 19 of 36
VCM
= (AV D D + VREF)/2
MAX
The minimum common-mode input level allows the AD9216 to accommodate ground-referenced inputs. Although optimum performance is achieved with a differential input, a single­ended source may be driven into VIN+ or VIN−. In this configuration, one input accepts the signal, while the opposite input should be set to midscale by connecting it to an appropriate reference. For example, a 2 V p-p signal may be applied to VIN+, while a 1 V reference is applied to VIN−.
Page 20
AD9216
2
The AD9216 then accepts an input signal varying between 2 V and 0 V. In the single-ended configuration, distortion performance may degrade significantly as compared to the differential case. However, the effect is less noticeable at lower input frequencies.
85
80
75
70
65
dB
60
55
50
45
40
0.25 0.75 1.25 1.75 2.25 2.75 ANALOG INPUT COMMON-MODE VOLTAGE (V)
Figure 29. Input Common-Mode Voltage Sensitivity

Differential Input Configurations

As previously detailed, optimum performance is achieved while driving the AD9216 in a differential input configuration. For baseband applications, the AD8138 differential driver provides excellent performance and a flexible interface to the ADC. The output common-mode voltage of the AD8138 is easily set to AVDD/2, and the driver can be configured in a Sallen-Key filter topology to provide band limiting of the input signal.
At input frequencies in the second Nyquist zone and above, the performance of most amplifiers is not adequate to achieve the true performance of the AD9216. This is especially true in IF under-sampling applications where frequencies in the 70 MHz to 200 MHz range are being sampled. For these applications, differential transformer coupling is the recommended input configuration, as shown in Figure 30.
V p-p
49.9
0.1µF
Figure 30. Differential Transformer Coupling
The signal characteristics must be considered when selecting a transformer. Most RF transformers saturate at frequencies below a few MHz, and excessive signal power can also cause core saturation, which leads to distortion.
2V p-p SFDR
2V p-p SNR
50
10pF
50
10pF
1k
1k
AVDD
VIN_A
AD9216
VIN_B
AGND
04775-009
04775-010
For dc-coupled applications, the AD8138, AD8139, or AD8351 can serve as a convenient ADC driver, depending on requirements. Figure 31 shows an example with the AD8138. The AD9216 PCB has an optional AD8351 on board, as shown in Figure 38 and Figure 39. The AD8351 typically yields better performance for frequencies greater than 30 MHz to 40 MHz.
0.1µF
SCALE/2
49.9
499
1.3k
2k
523
Figure 31. Driving the ADC with the AD8138
SENSE = GROUND
VIN+
FULL
AVDD/2 AVDD/2
VIN–
DIGITAL OUT = ALL ONES DIGITAL OUT = ALL ZEROES
Figure 32. Analog Input Full Scale (Full Scale = 2 V)
499
AD8138
499
33
20pF
33
AVDD
VIN+
AD9216
VIN–
AGND
04775-011
04775-012

Single-Ended Input Configuration

A single-ended input may provide adequate performance in cost-sensitive applications. In this configuration, there is a degradation in SFDR and distortion performance due to the large input common-mode swing. However, if the source impedances on each input are matched, there should be little effect on SNR performance.

CLOCK INPUT AND CONSIDERATIONS

Typical high speed ADCs use both clock edges to generate a variety of internal timing signals and, as a result, may be sensitive to clock duty cycle. Commonly, a 5% tolerance is required on the clock duty cycle to maintain dynamic performance characteristics.
The AD9216 provides separate clock inputs for each channel. The optimum performance is achieved with the clocks operated at the same frequency and phase. Clocking the channels asynchronously may degrade performance significantly. In some applications, it is desirable to skew the clock timing of adjacent channels. The AD9216’s separate clock inputs allow for clock timing skew (typically ±1 ns) between the channels without significant performance degradation.
Rev. 0 | Page 20 of 36
Page 21
AD9216
The AD9216 contains two clock duty cycle stabilizers, one for each converter, that retime the nonsampling edge, providing an internal clock with a nominal 50% duty cycle. Faster input clock rates (where it becomes difficult to maintain 50% duty cycles) can benefit from using DCS as a wide range of input clock duty cycles can be accommodated. Maintaining a 50% duty cycle clock is particularly important in high speed applications, when proper track-and-hold times for the converter are required to maintain high performance. The DCS can be enabled by tying the DCS pin high.
The duty cycle stabilizer uses a delay-locked loop to create the nonsampling edge. As a result, any changes to the sampling frequency require approximately 2 µs to 3 µs to allow the DLL to acquire and settle to the new rate.
High speed, high resolution ADCs are sensitive to the quality of the clock input. The degradation in SNR at a given full-scale input frequency (f
) due only to aperture jitter (tJ) can be
INPUT
calculated by
SNR degradation = 2 × log 10[1/2 × p × f
In the equation, the rms aperture jitter,
t
, represents the root-
J
INPUT
× tJ]
sum square of all jitter sources, which includes the clock input, analog input signal, and ADC aperture jitter specification. Under-sampling applications are particularly sensitive to jitter.
For optimal performance, especially in cases where aperture jitter may affect the dynamic range of the AD9216, it is important to minimize input clock jitter. The clock input circuitry should use stable references; for example, use analog power and ground planes to generate the valid high and low digital levels for the AD9216 clock input. 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.

POWER DISSIPATION AND STANDBY MODE

The power dissipated by the AD9216 is proportional to its sampling rates. The digital (DRVDD) power dissipation is determined primarily by the strength of the digital drivers and the load on each output bit. The digital drive current can be calculated by
The analog circuitry is optimally biased so that each speed grade provides excellent performance while affording reduced power consumption. Each speed grade dissipates a baseline power at low sample rates that increases with clock frequency.
Either channel of the AD9216 can be placed into standby mode independently by asserting the PWDN_A or PDWN_B pins. Time to go into or come out of standby mode is 5 cycles maximum when only one channel is being powered down. When both channels are powered down, VREF goes to ground, resulting in a wake-up time of ~7 mS dependent on decoupling capacitor values.
It is recommended that the input clock(s) and analog input(s) remain static during either independent or total standby, which results in a typical power consumption of 3 mW for the ADC. If the clock inputs remain active while in total standby mode, typical power dissipation of 10 mW results.
The minimum standby power is achieved when both channels are placed into full power-down mode (PDWN_A = PDWN_B = HI). Under this condition, the internal references are powered down. When either or both of the channel paths are enabled after a power-down, the wake-up time is directly related to the recharging of the REFT and REFB decoupling capacitors and to the duration of the power-down.
A single channel can be powered down for moderate power savings. The powered-down channel shuts down internal circuits, but both the reference buffers and shared reference remain powered on. Because the buffer and voltage reference remain powered on, the wake-up time is reduced to several clock cycles.

DIGITAL OUTPUTS

The AD9216 output drivers can interface directly with 3 V logic families. Applications requiring the ADC to drive large capacitive loads or large fanouts may require external buffers or latches because large drive currents tend to cause current glitches on the supplies that may affect converter performance.
The data format can be selected for either offset binary or twos complement. This is discussed in the Data Format section.
I
= V
DRVDD
where
N is the number of bits changing, and C
DRVDD
× C
LOAD
× f
CLOCK
× N
load on the digital pins that changed.
is the average
LOAD
Rev. 0 | Page 21 of 36
Page 22
AD9216

OUTPUT CODING

Table 8.
Code (VIN+) − (VIN−) Offset Binary Twos Complement
1023 > +0.998 V 11 1111 1111 01 1111 1111 1023 +0.998 V 11 1111 1111 01 1111 1111 1022 +0.996 V 11 1111 1110 01 1111 1110
• •
• • • 513 +0.002 V 10 0000 0001 00 0000 0001 512 +0.0 V 10 0000 0000 00 0000 0000 511 −0.002 V 01 1111 1111 11 1111 1111
• •
• • • 1 −0.998 V 00 0000 0001 10 0000 0001 0 −1.000 V 00 0000 0000 10 0000 0000 0 < −1.000 V 00 0000 0000 10 0000 0000

TIMING

The AD9216 provides latched data outputs with a pipeline delay of six clock cycles. Data outputs are available one propagation delay (t Figure 2 for a detailed timing diagram.
The length of the output data lines and loads placed on them should be minimized to reduce transients within the AD9216. These transients can detract from the converter’s dynamic performance. The lowest conversion rate of the AD9216 is 10 MSPS. At clock rates below 10 MSPS, dynamic performance may degrade.
) after the rising edge of the clock signal. Refer to
PD

DATA FORMAT

The AD9216 data output format can be configured for either twos complement or offset binary. This is controlled by the data format select pin (DFS). Connecting DFS to AGND produces offset binary output data. Conversely, connecting DFS to AVDD formats the output data as twos complement.
The output data from the dual ADCs can be multiplexed onto a single 10-bit output bus. The multiplexing is accomplished by toggling the MUX_SELECT bit, which directs channel data to the same or opposite channel data port. When MUX_SELECT is logic high, the Channel A data is directed to the Channel A output bus, and the Channel B data is directed to the Channel B output bus. When MUX_SELECT is logic low, the channel data is reversed, i.e., the Channel A data is directed to the Channel B output bus, and the Channel B data is directed to the Channel A output bus. By toggling the MUX_SELECT bit, multiplexed data is available on either of the output data ports.
If the ADCs are run with synchronized timing, this same clock can be applied to the MUX_SELECT bit. After the MUX_SELECT rising edge, either data port has the data for its respective channel; after the falling edge, the alternate channel’s data is placed on the bus. Typically, the other unused bus is disabled by setting the appropriate OEB high to reduce power consumption and noise. Figure 33 shows an example of multiplex mode. When multiplexing data, the data rate is two times the sample rate. Note that both channels must remain active in this mode and that each channel’s power-down pin must remain low.
A
A
–1
B
–1
0
B
0
B
–7
Figure 33. Example of Multiplexed Data Format Using the Channel A Output and the Same Clock Tied to CLK_A, CLK_B, and MUX_SELECT
A
1
B
1
A
B
–6
–6
A
2
B
2
A
B–5A–4B–4A
–5
A
A
3
B
3
A
4
B
4
B
–3
–3
A
5
B
5
A
B
–2
–2
A–1B
A
6
B
6
A0B0A1B
–1
7
B
7
A
8
B
1
8
ANALOG INPUT ADC A
ANALOG INPUT ADC B
CLK_A = CLK_B = MUX_SELECT
D0_A –D11_A
04775-013
Rev. 0 | Page 22 of 36
Page 23
AD9216

VOLTAGE REFERENCE

A stable and accurate 0.5 V voltage reference is built into the AD9216. The input range can be adjusted by varying the reference voltage applied to the AD9216, using either the internal reference with different external resistor configurations or an externally applied reference voltage. The input span of the ADC tracks reference voltage changes linearly.
If the ADC is being driven differentially through a transformer, the reference voltage can be used to bias the center tap (common-mode voltage).

Internal Reference Connection

A comparator within the AD9216 detects the potential at the SENSE pin and configures the reference into three 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 34), setting VREF to 1 V. If a resistor divider is connected, as shown in Figure 35, the switch is again set to the SENSE pin. This puts the reference amplifier in a noninverting mode with the VREF output defined as
VREF = 0.5 × (1 + R2/R1)
Note that optimum performance is obtained with VREF = 1.0 V; performance degrades as VREF (and full scale) reduces (see Figure 16). In all reference configurations, REFT and REFB drive the ADC 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.
VIN+
10µF
VIN–
ADC
CORE
VREF
0.1µF
SENSE
Figure 34. Internal Reference Configuration
SELECT
LOGIC
0.5V
AD9216
REFT
REFB
0.1µF
0.1µF
0.1µF
10µF
04775-014
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 Programmable Reference 0.2 V to VREF 0.5 × (1 + R2/R1) 2 × VREF (See Figure 35) Internal Fixed Reference AGND to 0.2 V 1.0 2.0
Rev. 0 | Page 23 of 36
Page 24
AD9216

External Reference Operation

The use of an external reference may be necessary to enhance the gain accuracy of the ADC or to improve the thermal drift characteristics. When multiple ADCs track one another, a single reference (internal or external) may be necessary to reduce gain matching errors to an acceptable level. A high precision external reference may also be selected to provide lower gain and offset temperature drift. Figure 36 shows the typical drift characteristics of the internal reference. 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 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. If the internal reference of the AD9216 is used to drive multiple converters to improve gain matching, the loading of the reference by the other converters must be considered. Figure 37 depicts how the internal reference voltage is affected by loading.
0.6
0.5
0.4
0.3 VREF = 1.0V
VREF ERROR (%)
0.2
0.1
0
40–20 0 20406080
0.05
0
–0.05
TEMPERATURE (°C)
Figure 36. Typical VREF Drift
04775-016
10µF
VIN+ VIN–
CORE
V
REF
10µF
SENSE
R2
R1
SELECT
LOGIC
AD9216
Figure 35. Programmable Reference Configuration
ADC
0.5V
REFT
REFB
0.1µF
0.1µF
0.1µF
10µF
–0.10
VREF ERROR (%)
–0.15
–0.20
–0.25
0 0.5 1.0 1.5 2.0 2.5 3.0
VREF = 1.0V
I
LOAD
(mA)
04775-017
Figure 37. VREF Accuracy vs. Load

Shared Reference Mode

The shared reference mode allows the user to connect the references from the dual ADCs together externally for
04775-015
superior gain and offset matching performance. If the ADCs are to function independently, the reference decoupling can be treated independently and can provide superior isolation between the dual channels. To enable shared reference mode, the SHARED_REF pin must be tied high, and the external differential references must be externally shorted. (REFT_A must be externally shorted to REFT_B, and REFB_A must be shorted to REFB_B.)
Rev. 0 | Page 24 of 36
Page 25
AD9216

DUAL ADC LFCSP PCB

The PCB requires a low jitter clock source, analog sources, and power supplies. The PCB interfaces directly with ADI’s standard dual-channel data capture board (HSC-ADC-EVAL-DC), which together with ADI’s ADC Analyzer™ software allows for quick ADC evaluation.

POWER CONNECTOR

Power is supplied to the board via three detachable 4-lead power strips.
Table 10. Power Connector
Terminal Comments
VCC1 3.0 V Analog supply for ADC VDD1 3.0 V Output supply for ADC VDL1 3.0 V Supply circuitry VREF Optional external VREF +5 V Optional op amp supply
−5 V Optional op amp supply
1
VCC, VDD, and VDL are the minimum required power connections.

ANALOG INPUTS

The evaluation board accepts a 2 V p-p analog input signal centered at ground at two SMB connectors, Input A and Input B. These signals are terminated at their respective primary side transformer. T1 and T2 are wideband RF transformers that provide the single-ended-to-differential conversion, allowing the ADC to be driven differentially, minimizing even-order harmonics. The analog signals can be low-pass filtered at the secondary transformer to reduce high frequency aliasing.

OPTIONAL OPERATIONAL AMPLIFIER

The PCB has been designed to accommodate an optional AD8139 op amp that can serve as a convenient solution for dc-coupled applications. To use the AD8139 op amp, remove C14, R4, R5, C13, R37, and R36. Place R22, R23, R30, and R24.

CLOCK

The clock inputs are buffered on the board at U5 and U6. These gates provide buffered clocks to the on-board latches U2 and U4, ADC input clocks, and DRA, DRB that are available at the output connector P3, P8. The clocks can be inverted at the timing jumpers labeled with the respective clocks. The clock paths also provide for various termination options. The ADC input clocks can be set to bypass the buffers at P2 to P9 and P10, P12. An optional clock buffer U3, U7 can also be placed. The clock inputs can be bridged at TIEA, TIEB (R20, R40) to allow one to clock both channels from one clock source.
Table 11. Jumpers
Terminal Comments
OEB A Output Enable for A Side PWDN A Power-Down A MUX Mux Input SHARED REF Shared Reference Input DR A Invert DR A LATA Invert A Latch Clock ENC A Invert Encode A OEB B Output Enable for B Side PWDN B Power-Down B DFS Data Format Select SHARED REF Shared Reference Input DR B Invert DR B LATB Invert B Latch Clock ENC B Invert Encode B

VOLTAGE REFERENCE

The ADC SENSE pin is brought out to E41, and the internal reference mode is selected by placing a jumper from E41 to ground (E27). External reference mode is selected by placing a jumper from E41 to E25 and E30 to E2. R56 and R45 allow for programmable reference mode selection.

DATA OUTPUTS

The ADC outputs are latched on the PCB at U2, U4. The ADC outputs have the recommended series resistors in line to limit switching transient effects on ADC performance.
Rev. 0 | Page 25 of 36
Page 26
AD9216 Preliminary Technical Data

LFCSP EVALUATION BOARD BILL OF MATERIALS (BOM)

Table 12.
No. Quantity Reference Designator Device Package Value
1 2 C1, C3 Capacitors 0201 20 pF
2 7 C2, C5, C7, C9, C10, C22, C36 Capacitors 0805 10 µF 3 44
C4, C6, C8, C11 to C15, C20, C21,
C24 to C27, C29 to C35, C39 to C61 4 6 C16 to C19, C37, C38 Capacitors TAJD 10 µF 5 2 C23, C28 Capacitors 0201 0.1 µF 6 6 J1 to J6 SMBs 7 3 P1, P4, P11 Power Connector Posts Z5.531.3425.0 Wieland 8 3 P1, P4, P11 Detachable Connectors 25.602.5453.0 Wieland 9 2 P31, P8 Connectors 10 4 R1, R2, R32, R34 Resistors 0402 36 Ω 11 10 R3, R6, R7, R8, R11, R14, R33, R42, R51, R61 Resistors 0402 50 Ω 12 4 R4, R5, R36, R37 Resistors 0402 33 Ω 13 9 R9, R10, R12, R13, R20, R35, R38, R40, R43 Resistors 0402 0 Ω 14 6 R15, R16, R18, R26, R29, R31 Resistors 0402 499 Ω 15 2 R17, R25 Resistors 0402 525 Ω 16 27
R19, R21, R27, R28, R39, R41, R44,
R46 to R49, R52, R54, R55, R5 to R60, R62 to R70 17 4 R22 to R24, R30 Resistors 0402 40 Ω 18 2 R45, R56 Resistors 0402 10 kΩ 19 1 R50 Resistor 0402 22 Ω 20 8 RZ1 to RZ6, RZ9, RZ10 Resistor Pack 220 Ω 21 2 T1, T2 Transformers AWT-1WT Mini-Circuits 22 1 U1 AD9216 LFCSP-64 23 2 U2, U425 SN74LVTH162374 TSSOP-48 24 2 U32, U7 SN74LVC1G0 SOT-70 25 2 U5, U6 SN74VCX86 SO-14 26 2 U11, U12 AD8139 SO-8/EP
1
P3, P8 implemented as one 80-pin connector SAMTEC TSW-140-08-L-D-RA.
2
U3, U7 not placed.
Capacitors 0402 0.1 µF
Resistors 0402 1000
Rev. 0 | Page 26 of 36
Page 27
Preliminary Technical Data AD9216

LFCSP PCB SCHEMATICS

VD
C58
0.1µF
C36
DUT CLOCK SELECTABLE
TO BE DIRECT OR BUFFERED
VD
VD
E15E14
E13 E12
VD
C25
0.1µF
ENCA
R33
100
VD
VD
0
10µF
4
5
Y
VCC
GND
NC
A
SN74LVC1G04
3
1
2
R42
100
R43
U7
14
4B134A
VCC
74LCX86
1B1Y2A2B2Y
1A
1234567
P12 P10
VD
R39
1k
TIEA
J6
R61
50
C56
0.1µF
MUX
VD
E9
E7
R65
1k
R64
1k
VD
P1
P4
E10
E17
VD
E20
E18
R63
1k
E6
E5
R66
–5V
+5V
EXT_VREF
VDD VDL
VD
EXT_VREFVDLVDD
+5V
–5V
VD
4123 4123 4123
P11
P5
VD
H3
R46
1k
DRA
0
R10
124Y113B103A9
E4VD
C40
0.1µF
J3
ENCODE A
C8
0.1µF
VDD
R62
1k
ENCA
1k
C45
C44
C43
C39
VD
C19
C18
C17
+ + + ++
C16
C38
+
C37
VDL
VDD
P7
P6
H1
R47
1k
MUX
TIEA
TIEB
E34 E16
BUFFERED
0
0
R38
C26
C4
D0A
42
REFB_A
7
0.1µF
10µF
AMPOUTAB
4
3
0.1µF
0.1µF
C9
8
R58
41
DRVDD1
VREF
VREF
PADS TO SHORT
J5
10µF
40
9
SEE
REFERENCES TOGETHER
1k
R20
R14
VDD
U1
SENSE
SENSE
BELOW
C29
0
R40
50
39
D13_B D13B38D12_B
OTR_B OTRB
DRGND1
REFB_B11REFT_B
10
REFT_B
REFB_B
C54
0.1µF
C7
10µF
0.1µF
C27
REFTA
REFTB
REFBA
P15
P16
VD
VD
E42
E43
R59
R57
1k
TO BE DIRECT OR
DUT CLOCK SELECTABLE
C57
D12B
D11B
35
37
36
D11_B
AGND214VIN_BB15VIN_B16AGND3
AVDD2
13
12
VD
C28
0.1µF
0.1µF
AMPOUTBB
REFBB
P18
P17
CTAPB
R60
1k
1k
C10
10µF
C22
D10_B D10B
6
1
C12
0.1µF
10µF
R37
D9_B D9B34D8_B D8B
5
2
CTAPB
0.1µF
VD
SN74LVC1G04
C3
33
5
1
33
20pF
4
3
AMPINB
AIN B
R6
VCC
NC
ENCB
100
VD
22
4
Y
GND
A
3
2
D7_B
32
D6_B
31
D5_B
30
DRVDD
29
DRGND
28
D4_B
27
D3_B
26
D2_B
25
D1_B
24
D0_B
23
OEB_B
22
PDWN_B
21
DFS
20
DCS
19
CLK_B
18
AVDD3
17
R36
T1
J1
CLKLATB
0
R12
R8
R50
7
100
U3
VD
62B5
2Y
GND
U5
3Y3A3B4Y4A4BVCC
8
9
P9
P13
P2
R52
1k
C42
0.1µF
TIEB
D7B
J2
D6B
0.1µF
D5B
C6
D4B
VDD
D3B D2B D1B D0B
ENCB
VD
C11
0.1µF
1011121314
E36
VD
33
R56
AMPOUTB
C13
0.1µF
VREF AND SENSE CIRCUIT
R7
50
0
0
8
R9
CLKLATA
R35
3Y
U6
GND
P14
R44
1k
E3
R41
1k
R11
50
D8A
D11A D13A
1µF
.
0 1µF
.
0 1µF
.
0
0.1µF
10µF
10µF
10µF
10µF
10µF
10µF
H4
H2
TO TIE CLOCKS TOGETHER
D5A
D4A
47
46
D6_A D6A48D5_A
D4_A
D3_A D3A45D2_A D2A44D1_A D1A43D0_A
D7_A D7A
49
D8_A
50
D9_A D9A
51
DRVDD2
52
DRGND2
53
D10_A D10A
54
D11_A
55
D12_A D12A
56
D13_A
57
OTR_A OTRA
58
OEB_A
59
PWDN_A
60 61 62
63 64
65
MUX_SEL
SH_REF CLK_A AVDD5 VD
EPAD
AGND2VIN_A3VIN_AB4AGND1
1
C23
C1
20pF
C24
5
AMPOUTA
R4
33
T2
C14
0.1µF
R3
50
AMPINA
J4
AIN A
AVDD16REFT_A
VD
0.1µF C55
C5
0.1µF
R5
33
CTAPA
6
5
1
2
CTAPA
C31
0.1µF
VD
R48
1k
0
41Y31B21A1
2A
R49
E35
R54
1k
R51
50
ENCODE B
SENSE
10k
E41
E25
VD
E37E38
DRB
1k
R70
C30
R45
E27
VD
R55
1k
R13
74LCX86
C41
0.1µF
VD
E31E33
R69
1k
VD
E26
VD
1k
E29
E21
R68
1k
0.1µF
VD
E40
E22
R67
VREF
C2
VD
1k
E24
10µF
10k
E30
E2
EXT_VREF
MTHOLE6
MTHOLE6
04775-038
MTHOLE6
MTHOLE6
Figure 38. PCB Schematic (1 of 3)
Rev. 0 | Page 27 of 36
Page 28
AD9216 Preliminary Technical Data
D9Q
D8Q
D7Q
D6Q
D5Q
D4Q
D3Q
D2Q
DRA
GND
D13P
D12P
D11P
D10P
GND
D13Q
D12Q
D11Q
D9P
D8P
D7P
D6P
D5P
D4P
D3P
D2P
D1P
D0P
DORP
DRB
D10Q
D1Q
D0Q
DORQ
DORP
D13P
16151413121110
220
RSO16ISO
D = INPUT
Q = OUTPUT
OE2
LE2
24
25
23
2Q8
2D8
26
R3R1R2 312
2Q7
2D7
RZ5
D12P
22
27
GND GND
39
37
39
37
P3
363840
40
D9P
D8P
D11P
R4
D7P
D10P
9
R8
R7
R6
R5
8
7
654
D6P
16151413121110
220
RZ6
RSO16ISO
11131517192123252729313335
11131517192123252729313335
D5P
D4P
D3P
D2P
R5
R4
R3R1R2
54312
13579
13579
HEADER40
246
8
10121416182022242628303234
246
8
101214161820222426283032343638
D13Q
D11Q
D10Q
D9Q
D12Q
D1P
D0P
9
R8
R7
R6
8
7
6
DORQ
16151413121110
220
RZ10
RSO16ISO
R3R1R2
312
R6
R5
R4
654
37
39
333537
39
P8
40
40
D6Q
D3Q
D4Q
D8Q
D7Q
9
R8
R7
8
7
D5Q
16151413121110
220
RZ9
R3R1R2
RSO16ISO
R5
R4
54312
11131517192123252729313335
1113151719212325272931
D0Q
D1Q
D2Q
9
R8
R7
R6
8
7
6
13579
13579
HEADER40
246
8
101214161820222426283032343638
246
8
101214161820222426283032343638
C50
0.1µF
C51
0.1µF
21
28
2Q6
2D6
20
29
2Q5
2D5
12
1Q7
1D7
37
11
GND
38
10
1Q6
GND
1D6
39
9
40
8
1Q5
1D5
41
VDL
5
6
4
7
1Q4
VCC
VCC
1D4
42
43
1Q3
1D3
44
GND
GND
45
1Q2
1D2
3
46
1Q1
1D1
2
47
1
OE1
LE1
48
SN74LVCH16373A
24
2Q8
OE2
U2
D = INPUT
Q = OUTPUT
LE2
2D8
25
VDL
13
14
16
17
19
15
18
2Q3
1Q8
2Q1
2Q2
2Q4
VCC
GND
VCC
2D4
30
31
1D8
2D1
2D2
2D3
GND
36
35
33
32
34
23
26
2Q7
2D7
VDL
13
14
16
17
19
20
22
21
2Q6
2D6
GND GND
29
27
28
2Q5
2D5
15
18
2Q1
2Q2
2Q3
2Q4
VCC
VCC
2D4
30
31
1Q8
GND
1D8
2D1
2D2
2D3
GND
36
35
33
32
34
12
37
1Q7
1D7
11
38
10
1Q6
GND
1D6
GND
39
9
40
1Q5
1D5
VDL
2
3
5
6
8
4
7
1Q4
VCC
VCC
1D4
43
41
42
1Q3
1D3
44
GND
GND
45
1Q2
1D2
46
1Q1
1D1
47
OE1
LE1
1
U4
SN74LVCH16373A
48
C52
0.1µF
C53
0.1µF
C46
0.1µF
C47
0.1µF
C48
0.1µF
C49
0.1µF
CLKLATA
16151413121110
220
RZ3
RSO16ISO
D13A
OTRA
R3R1R2 312
D12A
VDL
9
220
R8
R7
R6
R5
R4
8
7
D11A
D10A
654
D9A
RZ4
D8A
D7A
VDL
16151413121110
R4
R3R1R2
RSO16ISO
D3A
D6A
D4A
D5A
CLKLATA
9
R8
R7
R6
R5
8
7
6
54312
D2A
D0A
D1A
CLKLATB
16151413121110
220
RZ1
RSO16ISO
D13B
OTRB
VDL
9
220
R8
R7
R6
R5
R4
R3R1R2
8
7
654
312
D12B
D11B
D10B
D9B
RZ2
D8B
D7B
VDL
16151413121110
R4
R3R1R2
RSO16ISO
D5B
D6B
D4B
D3B
CLKLATB
9
R8
R7
R6
R5
8
7
6
54312
D0B
D2B
D1B
VDL
04775-039
Figure 39. PCB Schematic (2 of 3)
Rev. 0 | Page 28 of 36
Page 29
Preliminary Technical Data AD9216
C59
R18
C21
R19
1k
VD
R16
499
AMPINA
OP AMP INPUT OFF PIN ONE OF TRANSFORMER
R17
525
R21
9
C60
499
0.1µF
1k
1
–IN
EPAD
+IN
8
C32
0.1µF
+5V
R22
40
4
36
2
V+
VOCM
U11
+OUT
AMPOUTA
AD8139
–OUT
V–
NC
5
7
C33
0.1µF
–5V
R23
40
AMPOUTAB
AMPINB
C15
R26
499
C20
R28
1k
VD
R25
525
R29
499
R27
9
C34
C61
Figure 40. PCB Schematic (3 of 3)
R15
499
0.1µF
1k
1
–IN
EPAD
+IN
8
0.1µF
R31
499
C35
0.1µF
+5V
R30
40
4
36
2
V+
VOCM
U12
+OUT
AD8139
V–
–OUT
NC
5
7
–5V
R24
40
AMPOUTB AMPOUTBB
04775-040
Rev. 0 | Page 29 of 36
Page 30
AD9216 Preliminary Technical Data

LFCSP PCB LAYERS

Figure 41. PCB Top-Side Silkscreen
04775-041
Rev. 0 | Page 30 of 36
Page 31
Preliminary Technical Data AD9216
Figure 42. PCB Top-Side Copper Routing
04775-042
Rev. 0 | Page 31 of 36
Page 32
AD9216 Preliminary Technical Data
Figure 43. PCB Ground Layer
04775-043
Rev. 0 | Page 32 of 36
Page 33
Preliminary Technical Data AD9216
Figure 44. PCB Split Power Plane
04775-044
Rev. 0 | Page 33 of 36
Page 34
AD9216 Preliminary Technical Data
Figure 45. PCB Bottom-Side Copper Routing
04775-045
Rev. 0 | Page 34 of 36
Page 35
Preliminary Technical Data AD9216
Figure 46. PCB Bottom-Side Silkscreen

THERMAL CONSIDERATIONS

The AD9216 LFCSP package has an integrated heat slug that improves the thermal and electrical properties of the package when locally attached to a ground plane at the PCB. A thermal (filled) via array to a ground plane beneath the part provides a path for heat to escape the package, lowering junction temperature. Improved electrical performance also results from the reduction in package parasitics due to proximity of the ground plane. Recommended array is 0.3 mm vias on 1.2 mm pitch. θ Soldering the slug to the PCB is a requirement for this package.
= 26.4°C/W with this recommended configuration.
JA
04775-046
04775-047
Figure 47. Thermal Via Array
Rev. 0 | Page 35 of 36
Page 36
AD9216 Preliminary Technical Data

OUTLINE DIMENSIONS

0.30
0.25
0.18
64
1
PIN 1 INDICATOR
BSC SQ
PIN 1 INDICATOR
9.00
0.60 MAX
49
48
0.60 MAX
4.85 *
4.70 SQ
4.55
16
1.00
0.85
0.80
12° MAX
SEATING PLANE
TOP
VIEW
0.80 MAX
0.65 TYP
0.50 BSC
*
COMPLIANT TO JEDEC STANDARDS MO-220-VMMD
EXCEPT FOR EXPOSED PAD DIMENSION
8.75
BSC SQ
0.20 REF
0.45
0.40
0.35
0.05 MAX
0.02 NOM
33
32
EXPOSED PAD
(BOTTOM VIEW)
7.50 REF
17
Figure 48. 64-Lead Lead Frame Chip Scale Package [LFCSP]
9 mm × 9 mm Body (CP-64-1)
Dimensions shown in millimeters

ORDERING GUIDE

Model Temperature Range Package Description Package Option
AD9216BCPZ-105 AD9216BCPZRL7-1051 −40°C to +85°C 64-Lead Lead Frame Chip Scale Package (LFCSP) CP-64-1 AD9216-105PCB Evaluation Board with AD9216BCPZ-105
1
Z = Pb-free part.
1
−40°C to +85°C 64-Lead Lead Frame Chip Scale Package (LFCSP) CP-64-1
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners.
D04775–0–10/04(0)
Rev. 0 | Page 36 of 36
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