AD7328_15 Datasheet, PDF (1/37 Pages) Analog Devices – 8-Channel, Software-Selectable, True Bipolar Input, 12-Bit Plus Sign ADC

Data Sheet
8-Channel, Software-Selectable,
True Bipolar Input, 12-Bit Plus Sign ADC
AD7328
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
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
FUNCTIONAL BLOCK DIAGRAM
V_DD
REFIN/OUT V_CC
AD7328
V_IN0
V_IN1
V_IN2
V_IN3
V_IN4
V_IN5
V_IN6
V_IN7
I/P
MUX
CHANNEL
SEQUENCER
2.5V
VREF
T/H
13-BIT
SUCCESSIVE
APPROXIMATION
ADC
TEMPERATURE
INDICATOR
CONTROL LOGIC
AND REGISTERS
DOUT
SCLK
CS
DIN
AGND
V_SS
DGND
Figure 1.
V_DRIVE
GENERAL DESCRIPTION
The AD7328¹ 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.
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.
PRODUCT HIGHLIGHTS
1. The AD7328 can accept true bipolar analog input signals,
±10 V, ±5 V, ±2.5 V, and 0 V to +10 V unipolar signals.
2. The eight analog inputs can be configured as eight single-
ended inputs, four true differential input pairs, four pseudo
differential inputs, or seven pseudo differential inputs.
3. 1 MSPS serial interface. SPI®-/QSPI™-/DSP-/MICROWIRE™-
compatible interface.
4. Low power, 31 mW, at a maximum throughput rate of
1 MSPS.
5. Channel sequencer.
Table 1. Similar Product Selection
Device Throughput
Number Rate
Number of Bits
AD7329 1000 kSPS
12-bit plus sign
AD7327 500 kSPS
12-bit plus sign
AD7324 1000 kSPS
12-bit plus sign
AD7323 500 kSPS
12-bit plus sign
AD7322 1000 kSPS
12-bit plus sign
AD7321 500 kSPS
12-bit plus sign
Number of
Channels
8
8
4
4
2
2
1 _{Protected by U.S. Patent No. 6,731,232.}
Rev. C
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