10-Bit, 210 MSPS TxDAC
Digital-to-Analog Converter
AD9740W
Rev. 0
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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
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Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2010 Analog Devices, Inc. All rights reserved.
FEATURES
High performance member of pin-compatible
TxDAC product family
Excellent spurious-free dynamic range performance
SNR at 5 MHz output, 125 MSPS: 65 dB
Twos complement or straight binary data format
Differential current outputs: 2 mA to 20 mA
Power dissipation: 135 mW at 3.3 V
Power-down mode: 15 mW at 3.3 V
On-chip 1.2 V reference
CMOS-compatible digital interface
28-lead TSSOP package
Edge-triggered latches
Qualified for automotive applications
APPLICATIONS
Wideband communication transmit channel
Direct IF
Base stations
Wireless local loops
Digital radio links
Direct digital synthesis (DDS)
Instrumentation
FUNCTIONAL BLOCK DIAGRAM
1.2V RE F
REFLO
3.3V
CLOCK
SLEEP
REFIO
FS ADJ
DVDD
DCOM
CLOCK
DIG ITAL DATA INPUTS (DB9 TO DB0)
150pF
3.3
V
AVDD ACOM
AD9740W
CURRENT
SOURCE
ARRAY
IOUTA
IOUTB
MODE
SEGMENTED
SWITCHES
LATCHES
09489-001
LSB
SWITCHES
R
SET
0.1µF
Figure 1.
GENERAL DESCRIPTION
The AD9740W1 is a 10-bit resolution, wideband, third
generation member of the TxDA series of high performance,
low power CMOS digital-to-analog converters (DACs). The
TxDAC family, consisting of pin-compatible 8-, 10-, 12-, and
14-bit DACs, is specifically optimized for the transmit signal
path of communication systems. All of the devices share the
same interface options, small outline package, and pinout,
providing an upward or downward component selection path
based on performance, resolution, and cost. The AD9740W
offers exceptional ac and dc performance while supporting
update rates up to 210 MSPS.
The AD9740W’s low power dissipation makes it well suited for
portable and low power applications. Its power dissipation can
be further reduced to 60 mW with a slight degradation in
performance by lowering the full-scale current output. In
addition, a power-down mode reduces the standby power
dissipation to approximately 15 mW. A segmented current
source architecture is combined with a proprietary switching
technique to reduce spurious components and enhance
dynamic performance.
Edge-triggered input latches and a 1.2 V temperature-compensated
band gap reference have been integrated to provide a complete
monolithic DAC solution. The digital inputs support 3 V CMOS
logic families.
PRODUCT HIGHLIGHTS
1. The AD9740W is the 10-bit member of the pin-compatible
TxDAC family, which offers excellent INL and DNL
performance.
2. Data input supports twos complement or straight binary
data coding.
3. High speed, single-ended CMOS clock input supports
210 MSPS conversion rate.
4. Low power: Complete CMOS DAC function operates on
135 mW from a 2.7 V to 3.6 V single supply. The DAC full-
scale current can be reduced for lower power operation,
and a sleep mode is provided for low power idle periods.
5. On-chip voltage reference: The AD9740W includes a 1.2 V
temperature-compensated band gap voltage reference.
6. Industry-standard 28-lead TSSOP package.
1 Protected by U.S. Patent Numbers 5568145, 5689257, and 5703519.
AD9740W
Rev. 0 | Page 2 of 20
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description......................................................................... 1
Product Highlights ........................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
DC Specifications ......................................................................... 3
Dynamic Specifications ............................................................... 4
Digital Specifications ................................................................... 5
Absolute Maximum Ratings............................................................ 6
Thermal Characteristics .............................................................. 6
ESD Caution.................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Terminology ...................................................................................... 8
Typical Performance Characteristics ............................................. 9
Functional Description .................................................................. 12
Reference Operation .................................................................. 12
Reference Control Amplifier .................................................... 13
DAC Transfer Function ............................................................. 13
Analog Outputs .......................................................................... 13
Digital Inputs .............................................................................. 14
Clock Input.................................................................................. 14
DAC Timing................................................................................ 14
Power Dissipation....................................................................... 15
Applying the AD9740W............................................................ 15
Differential Coupling Using a Transformer............................... 15
Differential Coupling Using an Op Amp................................ 15
Single-Ended, Unbuffered Voltage Output............................. 16
Single-Ended, Buffered Voltage Output Configuration........ 16
Power and Grounding Considerations, Power Supply
Rejection...................................................................................... 16
Outline Dimensions ....................................................................... 18
Ordering Guide .......................................................................... 18
Automotive Products................................................................. 18
REVISION HISTORY
12/10—Revision 0: Initial Version
AD9740W
Rev. 0 | Page 3 of 20
SPECIFICATIONS
DC SPECIFICATIONS
TMIN to TMAX, AVDD = 3.3 V, DVDD = 3.3 V, IOUTFS = 20 mA, unless otherwise noted.
Table 1.
Parameter Min Typ Max Unit
RESOLUTION 10 Bits
DC ACCURACY1
Integral Linearity Error (INL) −0.75 ±0.15 +0.75 LSB
Differential Nonlinearity (DNL) −0.5 ±0.12 +0.5 LSB
ANALOG OUTPUT
Offset Error −0.02 +0.02 % of FSR
Gain Error (Without Internal Reference) −2 ±0.1 +2 % of FSR
Gain Error (With Internal Reference) −2 ±0.1 +2 % of FSR
Full-Scale Output Current2 2 20 mA
Output Compliance Range −1 +1.25 V
Output Resistance 100
Output Capacitance 5 pF
REFERENCE OUTPUT
Reference Voltage 1.14 1.20 1.26 V
Reference Output Current3 100 nA
REFERENCE INPUT
Input Compliance Range 0.1 1.25 V
Reference Input Resistance (External Reference) 7
Small Signal Bandwidth 0.5 MHz
TEMPERATURE COEFFICIENTS
Offset Drift 0 ppm of FSR/°C
Gain Drift (Without Internal Reference) ±50 ppm of FSR/°C
Gain Drift (With Internal Reference) ±100 ppm of FSR/°C
Reference Voltage Drift ±50 ppm/°C
POWER SUPPLY
Supply Voltages
AVDD 2.7 3.3 3.6 V
DVDD 2.7 3.3 3.6 V
Analog Supply Current (IAVDD) 33 36 mA
Digital Supply Current (IDVDD)4 8 9 mA
Supply Current Sleep Mode (IAVDD) 5 6 mA
Power Dissipation4 135 145 mW
Power Dissipation5 145 mW
Power Supply Rejection RatioAVDD6 −1 +1 % of FSR/V
Power Supply Rejection Ratio—DVDD6 −0.04 +0.04 % of FSR/V
OPERATING RANGE −40 +105 °C
1 Measured at IOUTA, driving a virtual ground.
2 Nominal full-scale current, IOUTFS, is 32 times the IREF current.
3 An external buffer amplifier with input bias current <100 nA should be used to drive any external load.
4 Measured at fCLOCK = 25 MSPS and fOUT = 1 MHz.
5 Measured as unbuffered voltage output with IOUTFS = 20 mA, 50 Ω RLOAD at IOUTA and IOUTB, fCLOCK = 100 MSPS, and fOUT = 40 MHz.
6 ±5% power supply variation.
AD9740W
Rev. 0 | Page 4 of 20
DYNAMIC SPECIFICATIONS
TMIN to TMAX, AVDD = 3.3 V, DVDD = 3.3 V, IOUTFS = 20 mA, differential transformer coupled output, 50 Ω doubly terminated, unless
otherwise noted.
Table 2.
Parameter Min Typ Max Unit
DYNAMIC PERFORMANCE
Maximum Output Update Rate (fCLOCK) 210 MSPS
Output Settling Time (tST) (to 0.1%)1 11 ns
Output Propagation Delay (tPD) 1 ns
Glitch Impulse 5 pV-s
Output Rise Time (10% to 90%)1 2.5 ns
Output Fall Time (10% to 90%)1 2.5 ns
Output Noise (IOUTFS = 20 mA)2 50 pA/√Hz
Output Noise (IOUTFS = 2 mA)2 30 pA/√Hz
Noise Spectral Density3 −143 dBm/Hz
AC LINEARITY
Spurious-Free Dynamic Range to Nyquist
fCLOCK = 25 MSPS; fOUT = 1.00 MHz
0 dBFS Output 66 79 dBc
−6 dBFS Output 75 dBc
−12 dBFS Output 67 dBc
−18 dBFS Output 61 dBc
fCLOCK = 65 MSPS; fOUT = 1.00 MHz 84 dBc
fCLOCK = 65 MSPS; fOUT = 2.51 MHz 80 dBc
fCLOCK = 65 MSPS; fOUT = 10 MHz 78 dBc
fCLOCK = 65 MSPS; fOUT = 15 MHz 76 dBc
fCLOCK = 65 MSPS; fOUT = 25 MHz 75 dBc
fCLOCK = 165 MSPS; fOUT = 21 MHz 70 dBc
fCLOCK = 165 MSPS; fOUT = 41 MHz 60 dBc
fCLOCK = 210 MSPS; fOUT = 40 MHz 67 dBc
fCLOCK = 210 MSPS; fOUT = 69 MHz 63 dBc
Spurious-Free Dynamic Range within a Window
fCLOCK = 25 MSPS; fOUT = 1.00 MHz; 2 MHz Span 79 dBc
fCLOCK = 50 MSPS; fOUT = 5.02 MHz; 2 MHz Span 90 dBc
fCLOCK = 65 MSPS; fOUT = 5.03 MHz; 2.5 MHz Span 90 dBc
fCLOCK = 125 MSPS; fOUT = 5.04 MHz; 4 MHz Span 90 dBc
Total Harmonic Distortion
fCLOCK = 25 MSPS; fOUT = 1.00 MHz −79 −65 dBc
fCLOCK = 50 MSPS; fOUT = 2.00 MHz −77 dBc
fCLOCK = 65 MSPS; fOUT = 2.00 MHz −77 dBc
fCLOCK = 125 MSPS; fOUT = 2.00 MHz −77 dBc
Signal-to-Noise Ratio
fCLOCK = 65 MSPS; fOUT = 5 MHz; IOUTFS = 20 mA 68 dB
fCLOCK = 65 MSPS; fOUT = 5 MHz; IOUTFS = 5 mA 64 dB
fCLOCK = 125 MSPS; fOUT = 5 MHz; IOUTFS = 20 mA 64 dB
fCLOCK = 125 MSPS; fOUT = 5 MHz; IOUTFS = 5 mA 62 dB
fCLOCK = 165 MSPS; fOUT = 5 MHz; IOUTFS = 20 mA 64 dB
fCLOCK = 165 MSPS; fOUT = 5 MHz; IOUTFS = 5 mA 62 dB
fCLOCK = 210 MSPS; fOUT = 5 MHz; IOUTFS = 20 mA 63 dB
fCLOCK = 210 MSPS; fOUT = 5 MHz; IOUTFS = 5 mA 60 dB
AD9740W
Rev. 0 | Page 5 of 20
Parameter Min Typ Max Unit
Multitone Power Ratio (8 Tones at 400 kHz Spacing)
fCLOCK = 78 MSPS; fOUT = 15.0 MHz to 18.2 MHz
0 dBFS Output 65 dBc
−6 dBFS Output 66 dBc
−12 dBFS Output 60 dBc
−18 dBFS Output 55 dBc
1 Measured single-ended into 50 Ω load.
2 Output noise is measured with a full-scale output set to 20 mA with no conversion activity. It is a measure of the thermal noise only.
3 Noise spectral density is the average noise power normalized to a 1 Hz bandwidth, with the DAC converting and producing an output tone.
DIGITAL SPECIFICATIONS
TMIN to TMAX, AVDD = 3.3 V, DVDD = 3.3 V, IOUTFS = 20 mA, unless otherwise noted.
Table 3.
Parameter Min Typ Max Unit
DIGITAL INPUTS1
Logic 1 Voltage 2.1 3 V
Logic 0 Voltage 0 0.9 V
Logic 1 Current −10 +10 μA
Logic 0 Current −10 +10 μA
Input Capacitance 5 pF
Input Setup Time (tS) 2.0 ns
Input Hold Time (tH) 1.5 ns
Latch Pulse Width (tLPW) 1.5 ns
1 Includes CLOCK pin in single-ended clock input mode.
0.1% 0.1%
t
S
t
H
t
PD
DB0 TO DB9
CLOCK
IOUTA
OR
IOUTB
t
LPW
t
ST
09489-002
Figure 2. Timing Diagram
AD9740W
Rev. 0 | Page 6 of 20
ABSOLUTE MAXIMUM RATINGS
Table 4.
Parameter
With
Respect to Min Max Unit
AVDD ACOM −0.3 +3.9 V
DVDD DCOM −0.3 +3.9 V
ACOM DCOM −0.3 +0.3 V
AVDD DVDD −3.9 +3.9 V
CLOCK, SLEEP DCOM −0.3 DVDD + 0.3 V
Digital Inputs, MODE DCOM −0.3 DVDD + 0.3 V
IOUTA, IOUTB ACOM −1.0 AVDD + 0.3 V
REFIO, REFLO, FS ADJ ACOM 0.3 AVDD + 0.3 V
Junction
Temperature
150 °C
Storage
Temperature
Range
−65 +150 °C
Lead Temperature
(10 sec)
300 °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
sections of this specification is not implied. Exposure to
absolute maximum ratings for extended periods may affect
device reliability.
THERMAL CHARACTERISTICS
Thermal Resistance
Table 5. Thermal Resistance1
Package Type θJA Unit
28-Lead TSSOP 67.7 °C/W
1 Thermal impedance measurements were taken on a 4-layer board in still air,
in accordance with EIA/JESD51-7.
ESD CAUTION
AD9740W
Rev. 0 | Page 7 of 20
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
NC = NO CONNECT. DO NOT
CONNE CT TO T HI S PIN.
28
27
26
25
24
23
22
21
20
19
18
17
16
15
DB8
DB7
DB6
DB3
DB4
DB5
(
MSB) DB9
DVDD
DCOM
MODE
IOUTA
RESERVED
AVDD
DB2
DB1
DB0
NC
NC
NC
IOUTB
ACOM
NC
SLEEP
NC REFLO
REFIO
FS ADJ
CLOCK
AD9740W
TOP VIEW
(No t to S cale)
09489-003
Figure 3. Pin Configuration
Table 6. Pin Function Descriptions
Pin No. Mnemonic Description
1 DB9 (MSB) Most Significant Data Bit (MSB).
2 to 9 DB8 to DB1 Data Bits 8 to 1.
10 DB0 (LSB) Least Significant Data Bit (LSB).
11 to 14, 19 NC No Internal Connection.
15 SLEEP Power-Down Control Input. Active high. Contains active pull-down circuit; it can be
left unterminated if not used.
16 REFLO Reference Ground when Internal 1.2 V Reference Used. Connect to ACOM for both
internal and external reference operation modes.
17 REFIO Reference Input/Output. Serves as reference input when using external reference.
Serves as 1.2 V reference output when using internal reference. Requires 0.1 μF capacitor
to ACOM when using internal reference.
18 FS ADJ Full-Scale Current Output Adjust.
20 ACOM Analog Common.
21 IOUTB Complementary DAC Current Output. Full-scale current when all data bits are 0s.
22 IOUTA DAC Current Output. Full-scale current when all data bits are 1s.
23 RESERVED Reserved. Do Not Connect to Common or Supply.
24 AVDD Analog Supply Voltage (3.3 V).
25 MODE Selects Input Data Format. Connect to DCOM for straight binary, DVDD for twos complement.
26 DCOM Digital Common.
27 DVDD Digital Supply Voltage (3.3 V).
28 CLOCK Clock Input. Data latched on positive edge of clock.
AD9740W
Rev. 0 | Page 8 of 20
TERMINOLOGY
Linearity Error (Also Called Integral Nonlinearity or INL)
Linearity error is defined as the maximum deviation of the
actual analog output from the ideal output, determined by a
straight line drawn from zero to full scale.
Differential Nonlinearity (or DNL)
DNL is the measure of the variation in analog value, normalized
to full scale, associated with a 1 LSB change in digital input code.
Monotonicity
A DAC is monotonic if the output either increases or remains
constant as the digital input increases.
Offset Error
The deviation of the output current from the ideal of zero is
called the offset error. For IOUTA, 0 mA output is expected
when the inputs are all 0s. For IOUTB, 0 mA output is expected
when all inputs are set to 1s.
Gain Error
The difference between the actual and ideal output span. The
actual span is determined by the output when all inputs are set
to 1s minus the output when all inputs are set to 0s.
Output Compliance Range
The range of allowable voltage at the output of a current output
DAC. Operation beyond the maximum compliance limits can
cause either output stage saturation or breakdown, resulting in
nonlinear performance.
Temperature Drift
Temperature drift is specified as the maximum change from the
ambient (25°C) value to the value at either TMIN or TMAX. For
offset and gain drift, the drift is reported in ppm of full-scale
range (FSR) per °C. For reference drift, the drift is reported in
ppm per °C.
Power Supply Rejection
The maximum change in the full-scale output as the supplies
are varied from nominal to minimum and maximum specified
voltages.
Settling Time
The time required for the output to reach and remain within a
specified error band about its final value, measured from the
start of the output transition.
Glitch Impulse
Asymmetrical switching times in a DAC give rise to undesired
output transients that are quantified by a glitch impulse. It is
specified as the net area of the glitch in pV-s.
Spurious-Free Dynamic Range
The difference, in dB, between the rms amplitude of the output
signal and the peak spurious signal over the specified bandwidth.
Total Harmonic Distortion (THD)
THD is the ratio of the rms sum of the first six harmonic
components to the rms value of the measured input signal. It is
expressed as a percentage or in decibels (dB).
Multitone Power Ratio
The spurious-free dynamic range containing multiple carrier
tones of equal amplitude. It is measured as the difference
between the rms amplitude of a carrier tone to the peak
spurious signal in the region of a removed tone.
150pF
1.2V RE F AVDD ACOM
REFLO
REFIO
FS ADJ
DVDD
DCOM
CLOCK
3.3V
DVDD
DCOM
IOUTA
IOUTB
AD9740W
SLEEP LATCHES
3.3V
MODE
09489-005
PMOS
CURRENT S OURCE
ARRAY
LSB
SWITCHES
SEG M E NT E D SWI T CHE S
FOR DB11 TO DB3
DIGITAL
DATA
TEKTRONIX AWG-2021
WITH OPTION 4
CLOCK
OUTPUT
LECROY 9210
PULS E G E NE RATOR
RETIMED
CLOCK
OUTPUT*
R
SET
2k
50
50
50
0.1µF
ROHDE AND SCHWARZ
FSEA30
SPECTRUM
ANALYZER
MINI-CIRCUITS
T1-1T
*AWG2021 CL OCK RET IME D
SO T HAT THE DI G ITAL DATA
TRANSIT I ONS O N FALLING EDG E
OF 50% DUT Y CYCL E CL OCK.
Figure 4. Basic AC Characterization Test Setup
AD9740W
Rev. 0 | Page 9 of 20
100
TYPICAL PERFORMANCE CHARACTERISTICS
f
OUT
(MHz)
SF DR (dBc)
95
45
50
55
60
65
70
75
80
85
90
110
210MSPS
09489-006
65MSPS
125MSPS
165MSPS
Figure 5. SFDR vs. fOUT at 0 dBFS
f
OUT
(MHz)
SFDR (dBc)
95
45
50
55
60
65
70
75
80
85
90
0 5 10 15 20 25
–12dBFS
–6dBFS
0dBFS
09489-007
Figure 6. SFDR vs. fOUT at 65 MSPS
f
OUT
(MHz)
SFDR ( dBc)
95
45
50
55
60
65
70
75
80
85
90
01052015 3025 4035 45
0dBFS
–6dBFS
–12dBFS
09489-008
Figure 7. SFDR vs. fOUT at 125 MSPS
f
OUT
(MHz)
SFDR ( dBc)
95
45
50
55
60
65
70
75
80
85
90
02010 30 40 50 60
–12dBFS
–6dBFS
0dBFS
09489-009
Figure 8. SFDR vs. fOUT at 165 MSPS
f
OUT
(MHz)
SFDR ( dBc)
95
45
50
55
60
65
70
75
80
85
90
0105152025
20mA
10mA
5mA
09489-010
Figure 9. SFDR vs. fOUT and IOUTFS at 65 MSPS and 0 dBFS
fOUT
(MHz)
SF DR (dBc)
95
90
45
55
50
65
60
75
70
85
80
02010 30 40 50 60 70 80
–12dBFS –6dBFS
0dBFS
09489-054
Figure 10. SFDR vs. fOUT at 210 MSPS
AD9740W
Rev. 0 | Page 10 of 20
210MSPS
09489-011
165MSPS
65MSPS
A
OUT
(dBFS)
SF DR (d Bc)
95
90
45
55
50
65
60
75
70
85
80
–25 –15–20 –10 –5 0
125MSPS
Figure 11. Single-Tone SFDR vs. AOUT at fOUT = fCLOCK/11
AOUT (d BFS)
SF DR ( dBc)
95
45
55
65
75
85
90
50
60
70
80
–25 –15–20 –10 –5 0
210MSPS
09489-012
165MSPS
125MSPS
65MSPS
Figure 12. Single-Tone SFDR vs. AOUT at fOUT = fCLOCK/5
f
CLOCK
(MSPS)
SNR (dB)
90
50
60
55
65
70
80
75
85
0609030 150
120 180 210
5mA
10mA
20mA
09489-013
Figure 13. SNR vs. fCLOCK and IOUTFS at fOUT = 5 MHz and 0 dBFS
A
OUT
(dBFS)
SFDR (dBc)
95
45
55
65
75
85
–25 –15–20 –10 –5 0
210MSPS ( 29, 31)
09489-014
78MSPS
165MSPS
125MSPS
65MSPS
Figure 14. Dual-Tone IMD vs. AOUT at fOUT = fCLOCK/7
CODE
ERROR (LSB)
0.25
–0.25
–0.15
–0.05
0.05
0.15
0512256 768 1024
09489-015
Figure 15. Typical INL
CODE
ERRO R (LS B )
0.25
–0.25
–0.15
–0.05
0.05
0.15
0512256 768 1024
09489-016
Figure 16. Typical DNL
AD9740W
Rev. 0 | Page 11 of 20
TE MPE RATURE (°C)
SF DR (dBc)
90
80
85
50
55
60
70
65
75
–40 0 20–20 40 60 80
4MHz
19MHz
34MHz
49MHz
09489-017
Figure 17. SFDR vs. Temperature at 165 MSPS, 0 dBFS
FRE Q UE NC Y ( M Hz)
MAG NIT UDE (d Bm)
0
–40
–30
–20
–10
–100
–90
–80
–60
–70
–50
111166213126 36
f
CLOCK
= 78MSPS
f
OUT
= 15.0MHz
SF DR = 77d Bc
AMPL IT UDE = 0d BF S
09489-018
Figure 18. Single-Tone SFDR
FRE QUE N CY (MHz)
MAGNIT UDE (d Bm)
0
–40
–30
–20
–10
–100
–90
–80
–60
–70
–50
111166213126 36
f
CLOCK
= 78MSPS
f
OUT1
= 15.0MHz
f
OUT2
= 15.4MHz
SF DR = 77 d Bc
AMPLI TUDE = 0d B FS
09489-019
Figure 19. Dual-Tone SFDR
FREQ UE NC Y (M Hz)
MAGNITUDE (dBm)
0
–40
–30
–20
–10
–100
–90
–80
–60
–70
–50
111166213126 36
f
CLOCK
= 78MSPS
f
OUT1
= 15.0M Hz
f
OUT2
= 15.4M Hz
f
OUT3
= 15.8M Hz
f
OUT4
= 16.2M Hz
SFDR = 72dBc
AMP LI TUDE = 0dBFS
09489-020
Figure 20. Four-Tone SFDR
DIGITAL DATA INPUTS ( DB11 TO DB0)
150pF
1.2V REF
AVDD ACOM
REFLO
PMOS
CURRENT S OURCE
ARRAY
3.3
V
REFIO
FS ADJ
DVDD
DCOM
CLOCK
3.3V IOUTA
IOUTB
AD9740W
SLEEP LATCHES
CLOCK
IOUTB
IOUTA
MODE
09489-021
V
DIFF
= V
OUTA
– V
OUTB
V
OUTB
V
OUTA
R
LOAD
50
R
LOAD
50
LSB
SWITCHES
SEGMENTED SWITCHES
FO R DB11 TO DB3
R
SET
2k
I
REF
V
REFIO
0.1µF
Figure 21. Simplified Block Diagram
AD9740W
Rev. 0 | Page 12 of 20
FUNCTIONAL DESCRIPTION
Figure 21 shows a simplified block diagram of the AD9740W.
The AD9740W consists of a DAC, digital control logic, and full-
scale output current control. The DAC contains a PMOS
current source array capable of providing up to 20 mA of full-
scale current (IOUTFS). The array is divided into 31 equal currents
that make up the five most significant bits (MSBs). The next
four bits, or middle bits, consist of 15 equal current sources
whose value is 1/16 of an MSB current source. The remaining
LSBs are binary weighted fractions of the middle bits current
sources. Implementing the middle and lower bits with current
sources, instead of an R-2R ladder, enhances its dynamic
performance for multitone or low amplitude signals and helps
maintain the DAC’s high output impedance (that is, >100 kΩ).
All of these current sources are switched to one or the other of
the two output nodes (that is, IOUTA or IOUTB) via PMOS
differential current switches. The switches are based on the
architecture that was pioneered in the AD9764 family, with
further refinements to reduce distortion contributed by the
switching transient. This switch architecture also reduces
various timing errors and provides matching complementary
drive signals to the inputs of the differential current switches.
The analog and digital sections of the AD9740W have separate
power supply inputs (that is, AVDD and DVDD) that can
operate independently over a 2.7 V to 3.6 V range. The digital
section, which is capable of operating at a clock rate of up to
210 MSPS, consists of edge-triggered latches and segment
decoding logic circuitry. The analog section includes the PMOS
current sources, the associated differential switches, a 1.2 V
band gap voltage reference, and a reference control amplifier.
The DAC full-scale output current is regulated by the reference
control amplifier and can be set from 2 mA to 20 mA via an
external resistor, RSET, connected to the full-scale adjust (FS ADJ)
pin. The external resistor, in combination with both the refer-
ence control amplifier and voltage reference, VREFIO, sets the
reference current, IREF, which is replicated to the segmented
current sources with the proper scaling factor. The full-scale
current, IOUTFS, is 32 times IREF.
REFERENCE OPERATION
The AD9740W contains an internal 1.2 V band gap reference.
The internal reference cannot be disabled, but can be easily
overridden by an external reference with no effect on perfor-
mance. Figure 22 shows an equivalent circuit of the band gap
reference. REFIO serves as either an output or an input depend-
ing on whether the internal or an external reference is used. To
use the internal reference, simply decouple the REFIO pin to
ACOM with a 0.1 μF capacitor and connect REFLO to ACOM
via a resistance less than 5 Ω. The internal reference voltage is
present at REFIO. If the voltage at REFIO is to be used any-
where else in the circuit, then an external buffer amplifier with
an input bias current of less than 100 nA should be used. An
example of the use of the internal reference is shown in Figure 24.
A
V
DD
7k
84µA
REFLO
REFIO
09489-057
Figure 22. Equivalent Circuit of Internal Reference
An external reference can be applied to REFIO, as shown in
Figure 23. The external reference can provide either a fixed
reference voltage to enhance accuracy and drift performance
or a varying reference voltage for gain control. Note that the
0.1 μF compensation capacitor is not required because the
internal reference is overridden, and the relatively high input
impedance of REFIO minimizes any loading of the external
reference.
150pF
1.2V REF
AVDD
REFLO
REFIO
FS ADJ
AD9740W
3.3
V
09489-023
CURRENT
SOURCE
ARRAY
Figure 23. External Reference Configuration
150pF
1.2V REF
AVDD
REFLO
3.3V
REFIO
FS ADJ
2k
0.1µF
AD9740W
09489-022
CURRENT
SOURCE
ARRAY
OPTIONAL
EXTERNAL
REF BUFFER
A
DDITION
A
L
LOAD
Figure 24. Internal Reference Configuration
AD9740W
Rev. 0 | Page 13 of 20
REFERENCE CONTROL AMPLIFIER
The AD9740W contains a control amplifier that is used to regu-
late the full-scale output current, IOUTFS. The control amplifier is
configured as a V-I converter, as shown in Figure 24, so that its
current output, IREF, is determined by the ratio of the VREFIO and
an external resistor, RSET, as stated in Equation 4. IREF is copied
to the segmented current sources with the proper scale factor to
set IOUTFS, as stated in Equation 3.
The control amplifier allows a wide (10:1) adjustment span of IOUTFS
over a 2 mA to 20 mA range by setting IREF between 62.5 μA and
625 μA. The wide adjustment span of IOUTFS provides several
benefits. The first relates directly to the power dissipation of
the AD9740W, which is proportional to IOUTFS (see the Power
Dissipation section). The second relates to a 20 dB adjustment,
which is useful for system gain control purposes.
The small signal bandwidth of the reference control amplifier is
approximately 500 kHz and can be used for low frequency small
signal multiplying applications.
DAC TRANSFER FUNCTION
The AD9740W provides complementary current outputs,
IOUTA and IOUTB. IOUTA provides a near full-scale current
output, IOUTFS, when all bits are high (that is, DAC CODE =
1023), while IOUTB, the complementary output, provides no
current. The current output appearing at IOUTA and IOUTB is
a function of both the input code and IOUTFS and can be
expressed as:
IOUTA = (DAC CODE/1023) × IOUTFS (1)
IOUTB = (1023 − DAC CODE)/1024 × IOUTFS (2)
where DAC CODE = 0 to 1023 (that is, decimal representation).
As mentioned previously, IOUTFS is a function of the reference
current IREF, which is nominally set by a reference voltage,
VREFIO, and external resistor, RSET. It can be expressed as:
IOUTFS = 32 × IREF (3)
where
IREF = VREFIO/RSET (4)
The two current outputs typically drive a resistive load directly
or via a transformer. If dc coupling is required, then IOUTA
and IOUTB should be directly connected to matching resistive
loads, RLOAD, that are tied to analog common, ACOM. Note that
RLOAD can represent the equivalent load resistance seen by
IOUTA or IOUTB, as would be the case in a doubly terminated
50 Ω or 75 Ω cable. The single-ended voltage output appearing
at the IOUTA and IOUTB nodes is simply
VOUTA = IOUTA × RLOAD (5)
VOUTB = IOUTB × RLOAD (6)
Note that the full-scale value of VOUTA and VOUTB should not
exceed the specified output compliance range to maintain
specified distortion and linearity performance.
VDIFF = (IOUTA IOUTB) × RLOAD (7)
Substituting the values of IOUTA, IOUTB, IREF, and VDIFF can be
expressed as:
VDIFF = {(2 × DAC CODE − 1023)/1024}
(32 × RLOAD/RSET) × VREFIO (8)
Equation 7 and Equation 8 highlight some of the advantages of
operating the AD9740W differentially. First, the differential
operation helps cancel common-mode error sources associated
with IOUTA and IOUTB, such as noise, distortion, and dc
offsets. Second, the differential code-dependent current and
subsequent voltage, VDIFF, is twice the value of the single-ended
voltage output (that is, VOUTA or VOUTB), thus providing twice the
signal power to the load.
Note that the gain drift temperature performance for a single-
ended (VOUTA and VOUTB) or differential output (VDIFF) of the
AD9740W can be enhanced by selecting temperature tracking
resistors for RLOAD and RSET due to their ratiometric relationship,
as shown in Equation 8.
ANALOG OUTPUTS
The complementary current outputs in each DAC, IOUTA,
and IOUTB can be configured for single-ended or differential
operation. IOUTA and IOUTB can be converted into complemen-
tary single-ended voltage outputs, VOUTA and VOUTB, via a load
resistor, RLOAD, as described in the DAC Transfer Function
section by Equation 5 through Equation 8. The differential
voltage, VDIFF, existing between VOUTA and VOUTB, can also be
converted to a single-ended voltage via a transformer or
differential amplifier configuration. The ac performance of
the AD9740W is optimum and specified using a differential
transformer-coupled output in which the voltage swing at
IOUTA and IOUTB is limited to ±0.5 V.
The distortion and noise performance of the AD9740W can be
enhanced when it is configured for differential operation. The
common-mode error sources of both IOUTA and IOUTB can
be significantly reduced by the common-mode rejection of a
transformer or differential amplifier. These common-mode
error sources include even-order distortion products and noise.
The enhancement in distortion performance becomes more
significant as the frequency content of the reconstructed
waveform increases and/or its amplitude decreases. This is due
to the first-order cancellation of various dynamic common-
mode distortion mechanisms, digital feedthrough, and noise.
Performing a differential-to-single-ended conversion via a
transformer also provides the ability to deliver twice the
reconstructed signal power to the load (assuming no source
termination). Because the output currents of IOUTA and
IOUTB are complementary, they become additive when pro-
cessed differentially. A properly selected transformer allows
the AD9740W to provide the required power and voltage levels
to different loads.
The output impedance of IOUTA and IOUTB is determined by
the equivalent parallel combination of the PMOS switches
associated with the current sources and is typically 100 kΩ in
AD9740W
Rev. 0 | Page 14 of 20
parallel with 5 pF. It is also slightly dependent on the output
voltage (that is, VOUTA and VOUTB) due to the nature of a PMOS
device. As a result, maintaining IOUTA and/or IOUTB at a
virtual ground via an I-V op amp configuration results in the
optimum dc linearity. Note that the INL/DNL specifications for
the AD9740W are measured with IOUTA maintained at a
virtual ground via an op amp.
IOUTA and IOUTB also have a negative and positive voltage
compliance range that must be adhered to in order to achieve
optimum performance. The negative output compliance range
of −1 V is set by the breakdown limits of the CMOS process.
Operation beyond this maximum limit can result in a
breakdown of the output stage and affect the reliability of the
AD9740W.
The positive output compliance range is slightly dependent on
the full-scale output current, IOUTFS. It degrades slightly from its
nominal 1.2 V for an IOUTFS = 20 mA to 1 V for an IOUTFS = 2 mA.
The optimum distortion performance for a single-ended or
differential output is achieved when the maximum full-scale
signal at IOUTA and IOUTB does not exceed 0.5 V.
DIGITAL INPUTS
The AD9740W digital section consists of 10 input bit channels
and a clock input. The 10-bit parallel data inputs follow stand-
ard positive binary coding, where DB9 is the most significant
bit (MSB) and DB0 is the least significant bit (LSB). IOUTA
produces a full-scale output current when all data bits are at
Logic 1. IOUTB produces a complementary output with the
full-scale current split between the two outputs as a function of
the input code.
DVDD
09489-024
DIGITAL
INPUT
Figure 25. Equivalent Digital Input
The digital interface is implemented using an edge-triggered
master/slave latch. The DAC output updates on the rising edge
of the clock and is designed to support a clock rate as high as
210 MSPS. The clock can be operated at any duty cycle that
meets the specified latch pulse width. The setup and hold times
can also be varied within the clock cycle as long as the specified
minimum times are met, although the location of these transition
edges can affect digital feedthrough and distortion performance.
Best performance is typically achieved when the input data
transitions on the falling edge of a 50% duty cycle clock.
CLOCK INPUT
The 28-lead TSSOP package option has a single-ended clock
input (CLOCK) that must be driven to rail-to-rail CMOS levels.
The quality of the DAC output is directly related to the clock
quality, and jitter is a key concern. Any noise or jitter in the
clock translates directly into the DAC output. Optimal perfor-
mance is achieved if the CLOCK input has a sharp rising edge,
because the DAC latches are positive edge triggered.
DAC TIMING
Input Clock and Data Timing Relationship
Dynamic performance in a DAC is dependent on the relation-
ship between the position of the clock edges and the time at
which the input data changes. The AD9740W is rising edge
triggered, and so exhibits dynamic performance sensitivity
when the data transition is close to this edge. In general, the
goal when applying the AD9740W is to make the data transition
close to the falling clock edge. This becomes more important as
the sample rate increases. Figure 26 shows the relationship of
SFDR to clock placement with different sample rates. Note that
at the lower sample rates, more tolerance is allowed in clock
placement, while at higher rates, more care must be taken.
–3 –2 2–1 0 1
65
75
CLOCK PL ACE MENT ( ns)
SFDR (dB)
3
55
45
35
60
70
50
40 50MHz S FDR
20MHz S FDR
50MHz S FDR
02911
-
026
09489-026
Figure 26. SFDR vs. Clock Placement @
fOUT = 20 MHz and 50 MHz (fCLOCK = 165 MSPS)
Sleep Mode Operation
The AD9740W has a power-down function that turns off the
output current and reduces the supply current to less than 6 mA
over the specified supply range of 2.7 V to 3.6 V and the tempera-
ture range. This mode can be activated by applying a Logic
Level 1 to the SLEEP pin. The SLEEP pin logic threshold is
equal to 0.5 Ω AVDD. This digital input also contains an active
pull-down circuit that ensures that the AD9740W remains
enabled if this input is left disconnected. The AD9740W takes
less than 50 ns to power down and approximately 5 μs to power
back up.
AD9740W
Rev. 0 | Page 15 of 20
POWER DISSIPATION
The power dissipation, PD, of the AD9740W is dependent on
several factors that include:
The power supply voltages (AVDD and DVDD)
The full-scale current output (IOUTFS)
The update rate (fCLOCK)
The reconstructed digital input waveform
The power dissipation is directly proportional to the analog
supply current, IAVDD, and the digital supply current, IDVDD. IAV DD
is directly proportional to IOUTFS, as shown in Figure 27, and is
insensitive to fCLOCK. Conversely, IDVDD is dependent on both the
digital input waveform, fCLOCK, and digital supply DVDD. Figure 28
shows IDVDD as a function of full-scale sine wave output ratios
(fOUT/fCLOCK) for various update rates with DVDD = 3.3 V.
I
OUTFS
(mA)
35
02
I
AVDD
(mA)
30
25
20
15
10
4 6 8 101214161820
09489-027
Figure 27. IAVDD vs. IOUTFS
20
0.01 10.1
14
16
18
12
10
8
6
4
2
0
165MSPS
210MSPS
65MSPS
125MSPS
I
DVDD
(mA)
RATIO (
f
OUT
/
f
CLOCK
)
09489-055
Figure 28. IDVDD vs. Ratio at DVDD = 3.3 V
APPLYING THE AD9740W
Output Configurations
The following sections illustrate some typical output configura-
tions for the AD9740W. Unless otherwise noted, it is assumed
that IOUTFS is set to a nominal 20 mA. For applications requiring
the optimum dynamic performance, a differential output
configuration is suggested. A differential output configuration
can consist of either an RF transformer or a differential op amp
configuration. The transformer configuration provides the
optimum high frequency performance and is recommended for
any application that allows ac coupling. The differential op amp
configuration is suitable for applications requiring dc coupling,
bipolar output, signal gain, and/or level shifting within the
bandwidth of the chosen op amp.
A single-ended output is suitable for applications requiring a
unipolar voltage output. A positive unipolar output voltage
results if IOUTA and/or IOUTB is connected to an appropriately
sized load resistor, RLOAD, referred to ACOM. This configuration
can be more suitable for a single-supply system requiring a dc-
coupled, ground referred output voltage. Alternatively, an amplifier
could be configured as an I-V converter, thus converting IOUTA
or IOUTB into a negative unipolar voltage. This configuration
provides the best dc linearity because IOUTA or IOUTB is main-
tained at a virtual ground.
DIFFERENTIAL COUPLING USING A TRANSFORMER
An RF transformer can be used to perform a differential-to-single-
ended signal conversion, as shown in Figure 29. A differentially
coupled transformer output provides the optimum distortion
performance for output signals whose spectral content lies
within the transformers pass band. An RF transformer, such
as the Mini-Circuits® T1–1T, provides excellent rejection of
common-mode distortion (that is, even-order harmonics) and
noise over a wide frequency range. It also provides electrical
isolation and the ability to deliver twice the power to the load.
Transformers with different impedance ratios can also be used
for impedance matching purposes. Note that the transformer
provides ac coupling only.
R
LOAD
AD9740W
OPTIONAL RDIFF
IOUTA
IOUTB
22
21
09489-030
MINI-CIRCUITS
T1-1T
Figure 29. Differential Output Using a Transformer
The center tap on the primary side of the transformer must be
connected to ACOM to provide the necessary dc current path
for both IOUTA and IOUTB. The complementary voltages
appearing at IOUTA and IOUTB (that is, VOUTA and VOUTB)
swing symmetrically around ACOM and should be maintained
with the specified output compliance range of the AD9740W. A
differential resistor, RDIFF, can be inserted in applications where
the output of the transformer is connected to the load, RLOAD,
via a passive reconstruction filter or cable. RDIFF is determined
by the transformer’s impedance ratio and provides the proper
source termination that results in a low VSWR. Note that approxi-
mately half the signal power is dissipated across RDIFF.
DIFFERENTIAL COUPLING USING AN OP AMP
An op amp can also be used to perform a differential-to-single-
ended conversion, as shown in Figure 30. The AD9740W is
configured with two equal load resistors, RLOAD, of 25 Ω. The
AD9740W
Rev. 0 | Page 16 of 20
differential voltage developed across IOUTA and IOUTB is
converted to a single-ended signal via the differential op amp
configuration. An optional capacitor can be installed across
IOUTA and IOUTB, forming a real pole in a low-pass filter. The
addition of this capacitor also enhances the op amps distortion
performance by preventing the DACs high slewing output from
overloading the op amps input.
AD9740W
IOUTA
IOUTB C
OPT
500
225
225
500
2525
AD8047
22
21
09489-031
Figure 30. DC Differential Coupling Using an Op Amp
The common-mode rejection of this configuration is typically
determined by the resistor matching. In this circuit, the differential
op amp circuit using the AD8047 is configured to provide some
additional signal gain. The op amp must operate off a dual
supply because its output is approximately ±1 V. A high speed
amplifier capable of preserving the differential performance of the
AD9740W while meeting other system level objectives (that is,
cost or power) should be selected. The op amps differential
gain, gain setting resistor values, and full-scale output swing
capabilities should all be considered when optimizing this
circuit.
The differential circuit shown in Figure 31 provides the
necessary level shifting required in a single-supply system. In
this case, AVDD, which is the positive analog supply for both
the AD9740W and the op amp, is also used to level shift the
differential output of the AD9740W to midsupply (that is,
AVDD/2). The AD8041 is a suitable op amp for this application.
AD9740W
IOUTA
IOUTB C
OPT
500
225
225
1k2525
AD8041
1kAVDD
22
21
09489-032
Figure 31. Single-Supply DC Differential Coupled Circuit
SINGLE-ENDED, UNBUFFERED VOLTAGE OUTPUT
Figure 32 shows the AD9740W configured to provide a unipo-
lar output range of approximately 0 V to 0.5 V for a doubly
terminated 50 Ω cable because the nominal full-scale current,
IOUTFS, of 20 mA flows through the equivalent RLOAD of 25 Ω. In
this case, RLOAD represents the equivalent load resistance seen by
IOUTA or IOUTB. The unused output (IOUTA or IOUTB) can
be connected to ACOM directly or via a matching RLOAD. Different
values of IOUTFS and RLOAD can be selected as long as the positive
compliance range is adhered to. One additional consideration
in this mode is the integral nonlinearity (INL), discussed in the
Analog Outputs section. For optimum INL performance, the
single-ended, buffered voltage output configuration is suggested.
AD9740W
IOUTA
IOUTB
50
25
V
OUTA
=0VTO0.5V
I
OUTFS
= 20mA
50
22
21
09489-033
Figure 32. 0 V to 0.5 V Unbuffered Voltage Output
SINGLE-ENDED, BUFFERED VOLTAGE OUTPUT
CONFIGURATION
Figure 33 shows a buffered single-ended output configuration
in which the op amp U1 performs an I-V conversion on the
AD9740W output current. U1 maintains IOUTA (or IOUTB) at
a virtual ground, minimizing the nonlinear output impedance
effect on the DAC’s INL performance as described in the Analog
Outputs section. Although this single-ended configuration typi-
cally provides the best dc linearity performance, its ac distortion
performance at higher DAC update rates can be limited by U1’s
slew rate capabilities. U1 provides a negative unipolar output
voltage, and its full-scale output voltage is simply the product of
RFB and IOUTFS. The full-scale output should be set within U1s
voltage output swing capabilities by scaling IOUTFS and/or RFB.
An improvement in ac distortion performance can result with a
reduced IOUTFS because U1 is required to sink less signal current.
AD9740W
IOUTA
IOUTB
C
OPT
200
U1
V
OUT
= I
OUTFS
× R
FB
I
OUTFS
=10mA
22
21
09489-034
R
FB
200
Figure 33. Unipolar Buffered Voltage Output
POWER AND GROUNDING CONSIDERATIONS,
POWER SUPPLY REJECTION
Many applications seek high speed and high performance
under less than ideal operating conditions. In these application
circuits, the implementation and construction of the printed
circuit board is as important as the circuit design. Proper RF
techniques must be used for device selection, placement, and
routing as well as power supply bypassing and grounding to
ensure optimum performance.
One factor that can measurably affect system performance is
the ability of the DAC output to reject dc variations or ac noise
superimposed on the analog or digital dc power distribution.
This is referred to as the power supply rejection ratio (PSRR).
For dc variations of the power supply, the resulting performance
of the DAC directly corresponds to a gain error associated with
the DAC’s full-scale current, IOUTFS. AC noise on the dc supplies
is common in applications where the power distribution is
AD9740W
Rev. 0 | Page 17 of 20
generated by a switching power supply. Typically, switching
power supply noise occurs over the spectrum from tens of
kilohertz to several megahertz. The PSRR vs. frequency of the
AD9740W AVDD supply over this frequency range is shown in
Figure 34.
FRE QUENCY (MHz)
85
40 1268100
PSRR (d B)
80
75
70
65
60
55
50
24
45
09489-035
Figure 34. Power Supply Rejection Ratio (PSRR)
Note that the ratio in Figure 34 is calculated as amps out/volts
in. Noise on the analog power supply has the effect of modulating
the internal switches, and therefore the output current. The
voltage noise on AVDD, therefore, is added in a nonlinear
manner to the desired IOUT. Due to the relative different size of
these switches, the PSRR is very code dependent. This can produce
a mixing effect that can modulate low frequency power supply
noise to higher frequencies. Worst-case PSRR for either one of
the differential DAC outputs occur when the full-scale current
is directed toward that output.
As a result, the PSRR measurement in Figure 34 represents a
worst-case condition in which the digital inputs remain static
and the full-scale output current of 20 mA is directed to the
DAC output being measured.
The following illustrates the effect of supply noise on the analog
supply. Suppose a switching regulator with a switching frequency
of 250 kHz produces 10 mV of noise and, for simplicity’s sake
(ignoring harmonics), all of this noise is concentrated at 250 kHz.
To calculate how much of this undesired noise appears as current
noise superimposed on the DACs full-scale current, IOUTFS, users
must determine the PSRR in dB using Figure 34 at 250 kHz. To
calculate the PSRR for a given RLOAD, such that the units of PSRR
are converted from A/V to V/V, adjust the curve in Figure 34 by
the scaling factor 20 Ω log (RLOAD). For instance, if RLOAD is 50 Ω,
then the PSRR is reduced by 34 dB (that is, PSRR of the DAC at
250 kHz, which is 85 dB in Figure 34, becomes 51 dB VOUT/VIN).
Proper grounding and decoupling should be a primary objec-
tive in any high speed, high resolution system. The AD9740W
features separate analog and digital supplies and ground pins to
optimize the management of analog and digital ground currents
in a system. In general, AVDD, the analog supply, should be
decoupled to ACOM, the analog common, as close to the chip
as physically possible. Similarly, DVDD, the digital supply,
should be decoupled to DCOM as close to the chip as physically
possible.
For those applications that require a single 3.3 V supply for both
the analog and digital supplies, a clean analog supply can be
generated using the circuit shown in Figure 35. The circuit
consists of a differential LC filter with separate power supply
and return lines. Lower noise can be attained by using low ESR
type electrolytic and tantalum capacitors.
FERRITE
BEADS AVDD
ACOM
09489-036
TTL/CMOS
LOGIC
CIRCUITS
3.3V
POWER SUPPLY
100µF
ELECT. 0.1µF
CER.
10µF TO
22µF
TANT.
Figure 35. Differential LC Filter for Single 3.3 V Applications
AD9740W
Rev. 0 | Page 18 of 20
OUTLINE DIMENSIONS
COMPLIANT TO JEDEC STANDARDS MO-153-AE
28 15
141
SEATING
PLANE
C
OPLANARIT
Y
0.10
1.20 MAX
6.40 BSC
0.65
BSC
PIN 1
0.30
0.19 0.20
0.09
4.50
4.40
4.30
0.75
0.60
0.45
9.80
9.70
9.60
0.15
0.05
Figure 36. 28-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-28)
Dimensions shown in millimeters
ORDERING GUIDE
Model1, 2 Temperature Range Package Description Package Option
AD9740WARUZ −40°C to +105°C 28-Lead TSSOP RU-28
AD9740WARUZRL7 −40°C to +105°C 28-Lead TSSOP RU-28
1 Z = RoHS Compliant Part.
2 W = Qualified for Automotive Applications.
AUTOMOTIVE PRODUCTS
The AD9740W models are available with controlled manufacturing to support the quality and reliability requirements of automotive
applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers
should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in
automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to
obtain the specific Automotive Reliability reports for these models.
AD9740W
Rev. 0 | Page 19 of 20
NOTES
AD9740W
Rev. 0 | Page 20 of 20
NOTES
©2010 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D09489-0-12/10(0)