
4-Channel, Software-Selectable, True
Bipolar Input, 12-Bit Plus Sign ADC
Data Sheet
Rev. B
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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
4 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
FUNCTIONAL BLOCK DIAGRAM
VIN0
DOUT
SCLK
CS
DIN
VDRIVE
VIN1
VIN2
VIN3
VDD
REFIN/OUT
VCC
AGND
VSS
DGND
CONTROL LOGIC
AND REGISTERS
13-BIT
SUCCESSIVE
APPROXIMATION
ADC
T/H
2.5V
VREF
I/P
MUX
CHANNEL
SEQUENCER
AD7324
04864-
001
Figure 1.
GENERAL DESCRIPTION
Th
e AD73241 is a 4-channel, 12-bit plus sign, successive
approximation 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 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, iCMOS
components can accept bipolar input signals while providing
increased performance, dramatically reduced power consumption,
and reduced package size.
Th
e 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 t
he AD7324 can be programmed
to be single-ended, true differential, or pseudo differential.
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 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.
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.
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, 31 mW maximum, at 1 MSPS throughput rate.
5. Channel sequencer.
Table 1. Similar Products Selection Table
Device
Number
Throughput
Rate
Number of bits
Number of
Channels
1000 kSPS
12-bit plus sign
8
1000 kSPS
12-bit plus sign
8
500 kSPS
12-bit plus sign
8
500 kSPS
12-bit plus sign
4
1000 kSPS
12-bit plus sign
2
500 kSPS
12-bit plus sign
2