
4-Channel, Software-Selectable, True
Bipolar Input, 12-Bit Plus Sign ADC
AD7324
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
Four 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
16-lead TSSOP package
i
CMOS
process technology
Rev. 0
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2005 Analog Devices, Inc. All rights reserved.
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FUNCTIONAL BLOCK DIAGRAM
V
IN
0
V
IN
1
V
IN
2
V
IN
3
DOUT
SCLK
CS
DIN
V
DRIVE
V
DD
REFIN/OUT
V
CC
AGND
V
SS
DGND
AND REGISTERS
ASUADC
T/H
2.5V
I/P
SCHANNEL
AD7324
0
Figure 1.
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
1.
The AD7324 can accept true bipolar analog input signals,
±10 V, ±5 V, ±2.5 V, and 0 V to +10 V unipolar signals.
The AD7324
1
is a 4-channel, 12-bit plus sign, successive
approximation ADC designed on the
i
CMOS (industrial
CMOS) process.
i
CMOS is a process combining high voltage
silicon with submicron CMOS and complementary bipolar
technologies. It enables the development 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,
i
CMOS
components can accept bipolar input signals while providing
increased performance, dramatically reduced power
consumption, and reduced package size.
2.
The four analog inputs can be configured as four single-
ended inputs, two true differential input pairs, two pseudo
differential inputs, or three pseudo differential inputs.
3.
1 MSPS serial interface. SPI-/QSPI-/DSP-/MICROWIRE-
compatible interface.
4.
Low power, 30 mW maximum, at 1 MSPS throughput rate.
5.
Table 1. Similar Products Selection Table
Device
Number
Rate
AD7329
250 kSPS
AD7328
1000 kSPS
AD7327
500 kSPS
AD7323
500 kSPS
AD7322
1000 kSPS
AD7321
500 kSPS
Channel sequencer.
The AD7324 can accept true bipolar analog input signals. The
AD7324 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 AD7324 can be programmed
to be single-ended, true differential, or pseudo differential.
Throughput
Number of
Channels
8
8
8
4
2
2
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
The ADC contains a 2.5 V internal reference. The AD7324 also
allows for external reference operation. If a 3 V reference is
applied to the REFIN/OUT pin, the AD7324 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
Protected by U.S. Patent No. 6,731,232.