FEATURES
FUNCTIONAL BLOCK DIAGRAM
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
8 analog input channels with channel sequencer
Single-ended, true differential, and pseudo differential
analog input capability
High analog input impedance
Low power: 21 mW
Temperature indicator
Full power signal bandwidth: 22 MHz
Internal 2.5 V reference
High speed serial interface
Power-down modes
20-lead TSSOP package
iCMOS process technology
REFIN/OUT
VDD
VCC
AD7328
VIN0
2.5V
VREF
VIN1
VIN2
VIN3
VIN4
VIN5
VIN6
VIN7
I/P
MUX
T/H
13-BIT
SUCCESSIVE
APPROXIMATION
ADC
TEMPERATURE
INDICATOR
DOUT
CONTROL LOGIC
AND REGISTERS
CHANNEL
SEQUENCER
SCLK
CS
DIN
VDRIVE
AGND
DGND
VSS
04852-001
Data Sheet
8-Channel, Software-Selectable,
True Bipolar Input, 12-Bit Plus Sign ADC
AD7328
Figure 1.
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD7328 is an 8-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.
1.
1
The AD7328 can accept true bipolar analog input signals. The
AD7328 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 AD7328 can be programmed to be
single-ended, true differential, or pseudo differential.
The ADC contains a 2.5 V internal reference. The AD7328 also
allows for external reference operation. If a 3 V reference is applied
to the REFIN/OUT pin, the AD7328 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.
Rev. C
2.
3.
4.
5.
The AD7328 can accept true bipolar analog input signals,
±10 V, ±5 V, ±2.5 V, and 0 V to +10 V unipolar signals.
The eight analog inputs can be configured as eight singleended inputs, four true differential input pairs, four pseudo
differential inputs, or seven pseudo differential inputs.
1 MSPS serial interface. SPI®-/QSPI™-/DSP-/MICROWIRE™compatible interface.
Low power, 31 mW, at a maximum throughput rate of
1 MSPS.
Channel sequencer.
Table 1. Similar Product Selection
Device
Number
AD7329
AD7327
AD7324
AD7323
AD7322
AD7321
1
Throughput
Rate
1000 kSPS
500 kSPS
1000 kSPS
500 kSPS
1000 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
4
4
2
2
Protected by U.S. Patent No. 6,731,232.
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