AD7322BRUZ Datasheet, PDF (1/36 Pages) Analog Devices – 2-Channel, Software-Selectable, True Bipolar Input, 1 MSPS, 12-Bit Plus Sign ADC

2-Channel, Software-Selectable, True
Bipolar Input, 1 MSPS, 12-Bit Plus Sign ADC
AD7322
FEATURES
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
GENERAL DESCRIPTION
The AD7322¹ 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 VDD and VSS
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 _{Protected by U.S. Patent No. 6,731,232.}
FUNCTIONAL BLOCK DIAGRAM
V_DD
REFIN/OUT V_CC
AD7322
V_IN0
V_IN1
I/P
MUX
2.5V
VREF
T/H
13-BIT
SUCCESSIVE
APPROXIMATION
ADC
CHANNEL
SEQUENCER
CONTROL LOGIC
AND REGISTERS
DOUT
SCLK
CS
DIN
AGND
V_SS
DGND
Figure 1.
V_DRIVE
PRODUCT HIGHLIGHTS
1. 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.
2. The two analog inputs can be configured as two single-
ended inputs, one true differential input, or one pseudo
differential input.
3. 1 MSPS serial interface. SPI-/QSPI™-/DSP-/MICROWIRE™-
compatible interface.
4. Low power, 31 mW maximum, at 1 MSPS throughput rate.
5. Channel sequencer.
Table 1. Similar Devices
Device Throughput
Number Rate
AD7329 1000 kSPS
AD7328 1000 kSPS
AD7327 500 kSPS
AD7324 1000 kSPS
AD7323 500 kSPS
AD7321 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
Rev. A
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