Data Sheet
FEATURES
2-Channel, Software-Selectable, True
Bipolar Input, 1 MSPS, 12-Bit Plus Sign ADC
AD7322
FUNCTIONAL BLOCK DIAGRAM
V
DD
REFIN/OUT
V
CC
12-bit plus sign SAR ADC
True bipolar input ranges
Software-selectable input ranges
±10 V, ±5 V, ±2.5 V, 0 V to +10 V
1 MSPS throughput rate
Two analog input channels with channel sequencer
Single-ended, true differential, and pseudo differential
analog input capability
High analog input impedance
Low power: 21 mW
Full power signal bandwidth: 22 MHz
Internal 2.5 V reference
High speed serial interface
Power-down modes
14-lead TSSOP package
iCMOS
process technology
AD7322
2.5V
VREF
I/P
MUX
T/H
V
IN
0
V
IN
1
13-BIT
SUCCESSIVE
APPROXIMATION
ADC
DOUT
CHANNEL
SEQUENCER
CONTROL LOGIC
AND REGISTERS
SCLK
CS
DIN
V
DRIVE
AGND
V
SS
DGND
04863-001
Figure 1.
GENERAL DESCRIPTION
The
AD7322
1
is a 2-channel, 12-bit plus sign, successive approx-
imation analog-to-digital converter (ADC) designed on the
iCMOS™
(industrial CMOS) process.
iCMOS
is a process
combining high voltage silicon with submicron CMOS and
complementary bipolar technologies. It enables the develop-
ment of a wide range of high performance analog ICs capable of
33 V operation in a footprint that no previous generation of high
voltage parts could achieve. Unlike analog ICs using conventional
CMOS processes,
iCMOS
components can accept bipolar input
signals while providing increased performance, dramatically
reduced power consumption, and reduced package size.
The
AD7322
can accept true bipolar analog input signals. The
AD7322
has four software-selectable input ranges, ±10 V, ±5 V,
±2.5 V, and 0 V to +10 V. Each analog input channel can be
independently programmed to one of the four input ranges.
The analog input channels on the
AD7322
can be programmed
to be single-ended, true differential, or pseudo differential.
The ADC contains a 2.5 V internal reference. The
AD7322
also
allows for external reference operation. If a 3 V reference is
applied to the REFIN/OUT pin, the
AD7322
can accept a true
bipolar ±12 V analog input. Minimum ±12 V V
DD
and V
SS
supplies are required for the ±12 V input range. The ADC has a
high speed serial interface that can operate at throughput rates
up to 1 MSPS.
1
PRODUCT HIGHLIGHTS
1.
2.
The
AD7322
can accept true bipolar analog input signals,
±10 V, ±5 V, and ±2.5 V, and 0 V to +10 V unipolar signals.
The two analog inputs can be configured as two single-
ended inputs, one true differential input, or one pseudo
differential input.
1 MSPS serial interface. SPI-/QSPI™-/DSP-/MICROWIRE™-
compatible interface.
Low power, 31 mW maximum, at 1 MSPS throughput rate.
Channel sequencer.
3.
4.
5.
Table 1. Similar Devices
Device
Number
AD7329
AD7328
AD7327
AD7324
AD7323
AD7321
Throughput
Rate
1000 kSPS
1000 kSPS
500 kSPS
1000 kSPS
500 kSPS
500 kSPS
Number of bits
12-bit plus sign
12-bit plus sign
12-bit plus sign
12-bit plus sign
12-bit plus sign
12-bit plus sign
Number of
Channels
8
8
8
4
4
2
Protected by U.S. Patent No. 6,731,232.
Document Feedback
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2005–2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
IMPORTANT LINKS for the
AD7322*
Last content update 12/22/2013 04:27 pm
SIMILAR PRODUCTS & PARAMETRIC SELECTION TABLES
Find Similar Products By Operating Parameters
Low Resolution - Simultaneous Sampling 12-Bit PulSAR ADCs
Low Resolution - Muxed 8/10/12/13-Bit PulSAR ADCs
DESIGN COLLABORATION COMMUNITY
Collaborate Online
with the ADI support team and other designers
about select ADI products.
Follow us on Twitter:
www.twitter.com/ADI_News
Like us on Facebook:
www.facebook.com/AnalogDevicesInc
DOCUMENTATION
MS-2210:
Designing Power Supplies for High Speed ADC
SUGGESTED COMPANION PRODUCTS
Recommended Input Buffer Amplifiers for the AD7322
For low noise and low power applications, we recommend the
ADA4841-1, ADA4932-1,
the dual
ADA4841-2
or the low cost
AD8137.
For low noise and high frequency, we recommend the
AD8021, ADA4899-1
or the dual
AD8022.
For low noise and low frequency at high supply voltages( up to
+/-18V), we suggest the
AD8597, ADA4627-1
or the dual
AD8599.
For low noise and low frequency applications at medium
supply voltages( up to +/-13V), we suggest the
AD8610
or the
dual
AD8620.
Recommended External References for the AD7322
For a precision 2.5V reference, we recommend
AD780,
AD1582, ADR431
or the
ADR391.
For a precision 3.0V reference, we recommend
AD780
or the
REF193.
DESIGN SUPPORT
Submit your support request here:
Linear and Data Converters
Embedded Processing and DSP
Americas:
Europe:
China:
India:
Russia:
Telephone our Customer Interaction Centers toll free:
1-800-262-5643
00800-266-822-82
4006-100-006
1800-419-0108
8-800-555-45-90
Quality and Reliability
Lead(Pb)-Free Data
SAMPLE & BUY
AD7322
View Price & Packaging
Request Evaluation Board
Request Samples
Check Inventory & Purchase
Find Local Distributors
EVALUATION KITS & SYMBOLS & FOOTPRINTS
View the Evaluation Boards and Kits page for documentation and
purchasing
Symbols and Footprints
* This page was dynamically generated by Analog Devices, Inc. and inserted into this data sheet.
Note: Dynamic changes to the content on this page (labeled 'Important Links') does not
constitute a change to the revision number of the product data sheet.
This content may be frequently modified.
Powered by TCPDF (www.tcpdf.org)
AD7322
TABLE OF CONTENTS
Features .............................................................................................. 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Product Highlights ........................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Specifications .................................................................. 6
Absolute Maximum Ratings............................................................ 7
ESD Caution .................................................................................. 7
Pin Configuration and Function Descriptions ............................. 8
Typical Performance Characteristics ............................................. 9
Terminology .................................................................................... 13
Theory of Operation ...................................................................... 15
Circuit Information .................................................................... 15
Converter Operation .................................................................. 15
Analog Input Structure .............................................................. 16
Typical Connection Diagram ................................................... 18
Analog Input ............................................................................... 18
Driver Amplifier Choice ............................................................ 20
Registers ........................................................................................... 21
Addressing Registers .................................................................. 21
Data Sheet
Control Register ......................................................................... 22
Range Register ............................................................................ 24
Sequencer Operation ..................................................................... 25
Reference ..................................................................................... 26
V
DRIVE
............................................................................................ 26
Modes of Operation ....................................................................... 27
Normal Mode (PM1 = PM0 = 0) ............................................. 27
Full Shutdown Mode (PM1 = PM0 = 1) ................................. 27
Autoshutdown Mode (PM1 = 1, PM0 = 0) ............................. 28
Autostandby Mode (PM1 = 0, PM0 = 1) ................................ 28
Power vs. Throughput Rate ....................................................... 29
Serial Interface ................................................................................ 30
Microprocessor Interfacing ........................................................... 31
AD7322 to ADSP-21xx .............................................................. 31
AD7322 to ADSP-BF53x ........................................................... 31
Application Hints ........................................................................... 32
Layout and Grounding .............................................................. 32
Power Supply Configuration .................................................... 32
Outline Dimensions ....................................................................... 33
Ordering Guide .......................................................................... 33
REVISION HISTORY
12/13—Rev. A to Rev. B
Changes to Circuit Information Section and Table 6 ................ 15
Changes to Addressing Registers Section.................................... 21
Changes to Power Supply Configuration Section ...................... 32
1/10—Rev. 0 to Rev. A
Changes to Power Requirements, Normal Mode (Operational),
I
CC
and I
DRIVE
Parameter; and Power Dissipation, Normal Mode
Parameter, Table 2............................................................................. 5
Changes to Endnote 1, Table 4 ........................................................ 7
Changes to Table 6 .......................................................................... 15
Changes to Figure 25 and Figure 26 ............................................. 16
Changes to Figure 30 and Figure 31............................................. 17
Changes to Figure 33 and Figure 34............................................. 18
Changes to Figure 39...................................................................... 19
Changes to Figure 40 and Figure 41............................................. 20
Changes to Autostandby Mode (PM1 = 0, PM = 1) Section .... 28
Changes to Table 14 and Table 15 ................................................ 31
Added Power Supply Configuration Section .............................. 32
Added Table 16; Renumbered Sequentially ................................ 32
Added Figure 53; Renumbered Sequentially .............................. 32
Updated Outline Dimensions ....................................................... 33
12/05—Revision 0: Initial Version
Rev. B | Page 2 of 36
Data Sheet
SPECIFICATIONS
AD7322
Unless otherwise noted, V
DD
= 12 V to 16.5 V, V
SS
= −12 V to −16.5 V, V
CC
= 4.75 V to 5.25 V, V
DRIVE
= 2.7 V to 5.25 V, V
REF
= 2.5 V to 3.0 V
internal/external, f
SCLK
= 20 MHz, f
S
= 1 MSPS, T
A
= T
MAX
to T
MIN
; for V
CC
< 4.75 V, all specifications are typical.
Table 2.
Parameter
DYNAMIC PERFORMANCE
Signal-to-Noise Ratio (SNR)
2
1
Min
76
72.5
75
B Version
Typ
Max
Unit
dB
dB
dB
dB
dB
dB
Signal-to-Noise + Distortion (SINAD)
2
76
72
72.5
Total Harmonic Distortion (THD)
2
−82
−77
−80
Peak Harmonic or Spurious Noise
(SFDR)
2
−82
−78
−79
Intermodulation Distortion (IMD)
2
Second-Order Terms
Third-Order Terms
Aperture Delay
3
Aperture Jitter
3
Common-Mode Rejection Ratio
(CMRR)
2
Channel-to-Channel Isolation
2
Full Power Bandwidth
DC ACCURACY
−80
−80
dB
dB
dB
dB
dB
dB
dB
dB
Test Conditions/Comments
f
IN
= 50 kHz sine wave
Differential mode
Single-ended/pseudo differential mode
Differential mode; ±2.5 V and ±5 V ranges
Differential mode; 0 V to +10 V and ±10 V ranges
Single-ended/pseudo differential mode;
±2.5 V and ±5 V ranges
Single-ended/pseudo differential mode;
0 V to +10 V and ±10 V ranges
Differential mode; ±2.5 V and ±5 V ranges
Differential mode; 0 V to +10 V and ±10 V ranges
Single-ended/pseudo differential mode;
±2.5 V and ±5 V ranges
Single-ended/pseudo differential mode;
0 V to +10 V and ±10 V ranges
Differential mode; ±2.5 V and ±5 V ranges
Differential mode; 0 V to +10 V and ±10 V ranges
Single-ended/pseudo differential mode;
±2.5 V and ±5 V ranges
Single-ended/pseudo differential mode;
0 V to +10 V and ±10 V ranges
fa = 50 kHz, fb = 30 kHz
−88
−90
7
50
−79
−72
22
5
dB
dB
ns
ps
dB
dB
MHz
MHz
Up to 100 kHz ripple frequency; see Figure 17
f
IN
on unselected channels up to 100 kHz; see Figure 14
At 3 dB
At 0.1 dB
All dc accuracy specifications are typical for 0 V to
10 V mode
Single-ended/pseudo differential mode:
1 LSB = FSR/4096; unless otherwise noted
Differential mode: 1 LSB = FSR/8192; unless
otherwise noted
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Single-ended/pseudo differential mode
(LSB = FSR/8192)
Resolution
No Missing Codes
13
12-bit plus
sign (13 bits)
11-bit plus
sign (12 bits)
±1.1
±1
−0.7/+1.2
Bits
Bits
Bits
LSB
LSB
LSB
Integral Nonlinearity
2
Rev. B | Page 3 of 36
AD7322
Parameter
Differential Nonlinearity
2
1
Data Sheet
Min
B Version
Typ
Max
−0.9/+1.5
±0.9
−0.7/+1
Unit
LSB
LSB
LSB
−4/+9
−7/+10
±0.6
±0.5
±8
±14
±0.5
±0.5
±4
±7
±0.5
±0.5
±8.5
±7.5
±0.5
±0.5
±4
±6
±0.5
±0.5
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
Test Conditions/Comments
Differential mode; guaranteed no missing codes to
13 bits
Single-ended mode; guaranteed no missing codes
to 12 bits
Single-ended/pseudo differential mode
(LSB = FSR/8192)
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Single-ended/pseudo differential mode
Differential mode
Reference = 2.5 V; see Table 6
V
DD
= 10 V min, V
SS
= −10 V min, V
CC
= 2.7 V to 5.25 V
V
DD
= 5 V min, V
SS
= −5 V min, V
CC
= 2.7 V to 5.25 V
V
DD
= 5 V min, V
SS
= − 5 V min, V
CC
= 2.7 V to 5.25 V
V
DD
= 10 V min, V
SS
= AGND min, V
CC
= 2.7 V to 5.25 V
V
DD
= 16.5 V, V
SS
= −16.5 V, V
CC
= 5 V; see Figure 40
and Figure 41
Reference = 2.5 V; range = ±10 V
Reference = 2.5 V; range = ±5 V
Reference = 2.5 V; range = ±2.5 V
Reference = 2.5 V; range = 0 V to +10 V
V
IN
= V
DD
or V
SS
Per channel, V
IN
= V
DD
or V
SS
When in track, ±10 V range
When in track, ±5 V and 0 V to +10 V range
When in track, ±2.5 V range
When in hold, all ranges
Offset Error
2, 4
Offset Error Match
2, 4
Gain Error
2, 4
Gain Error Match
2, 4
Positive Full-Scale Error
2, 5
Positive Full-Scale Error Match
2, 5
Bipolar Zero Error
2, 5
Bipolar Zero Error Match
2, 5
Negative Full-Scale Error
2, 5
Negative Full-Scale Error Match
2, 5
ANALOG INPUT
Input Voltage Ranges
(Programmed via Range Register)
±10
±5
±2.5
0 to 10
V
V
V
V
Pseudo Differential V
IN
(−) Input
Range
±3.5
±6
±5
+3/−5
DC Leakage Current
Input Capacitance
3
±80
3
13.5
16.5
21.5
3
2.5
10
2.5
±5
±10
3
7
25
3
±1
V
V
V
V
nA
nA
pF
pF
pF
pF
V
µA
pF
V
mV
mV
ppm/°C
Ω
REFERENCE INPUT/OUTPUT
Input Voltage Range
Input DC Leakage Current
Input Capacitance
Reference Output Voltage
Reference Output Voltage Error at
25°C
Reference Output Voltage
T
MIN
to T
MAX
Reference Temperature Coefficient
Reference Output Impedance
Rev. B | Page 4 of 36
Real-time operating system RTOS
京公网安备 11010802033920号
EEWORLD
