AD7656ABSTZ Datasheet, PDF (1/28 Pages) List of Unclassifed Manufacturers – 250 kSPS, 6-Channel, Simultaneous Sampling, Bipolar 16-Bit ADC

Data Sheet
250 kSPS, 6-Channel, Simultaneous
Sampling, Bipolar 16-Bit ADC
AD7656A
FEATURES
6 independent analog-to-digital converters (ADCs)
True bipolar analog inputs
Pin-/software-selectable ranges: ±10 V or ±5 V
Fast throughput rate: 250 kSPS
iCMOS® process technology
Low power: 140 mW at 250 kSPS with 5 V supplies
Wide input bandwidth
86.5 dB SNR at 50 kHz input frequency
On-chip reference and reference buffers
Parallel, serial, and daisy-chain interface modes
High speed serial interface
Serial peripheral interface (SPI)/QSPI™/MICROWIRE®/DSP
compatible
Power-down mode: 100 mW maximum
64-lead LQFP
Improved power supply sequencing (PSS) robustness
APPLICATIONS
Power line monitoring systems
Instrumentation and control systems
Multi-axis positioning systems
FUNCTIONAL BLOCK DIAGRAM
V_DD
CONVST A CONVST B CONVST C AV_CC DV_CC
REF
V1 T/H
BUF
CLK
OSC
CONTROL
LOGIC
16-BIT SAR
OUTPUT
DRIVERS
V2 T/H
V3 T/H
BUF
16-BIT SAR
16-BIT SAR
V4 T/H
V5 T/H
BUF
16-BIT SAR
16-BIT SAR
OUTPUT
DRIVERS
OUTPUT
DRIVERS
OUTPUT
DRIVERS
V6 T/H
V_SS
16-BIT SAR
AD7656A
AGND DGND
Figure 1.
CS
SER/PAR/SEL
V_DRIVE
STBY
DB8/DOUT A
SCLK
DB9/DOUT B
DB10/DOUT C
DATA/
CONTROL
LINES
RD
WR/REF_EN/DIS
GENERAL DESCRIPTION
The AD7656A¹ contains six 16-bit, fast, low power, successive
approximation analog-to-digital converters (ADCs) all in the
one package that is designed on the iCMOS® process (industrial
CMOS). 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 devices could achieve. Unlike
analog ICs using conventional CMOS processes, iCMOS
components can accept bipolar input signals while providing
increased performance, which dramatically reduces power
consumption and package size.
The AD7656A features throughput rates of up to 250 kSPS. It
contains wide bandwidth (12 MHz), track-and-hold amplifiers
that can handle input frequencies up to 12 MHz.
The conversion process and data acquisition are controlled
using CONVST x signals and an internal oscillator. Three
CONVST x pins (CONVST A, CONVST B, and CONVST C)
allow independent, simultaneous sampling of the three ADC
pairs. The AD7656A has a high speed parallel and serial interface,
allowing the device to interface with microprocessors or digital
signal processors (DSPs). In serial interface mode, the AD7656A
has a daisy-chain feature that allows multiple ADCs to connect
to a single serial interface. The AD7656A can accommodate
true bipolar input signals in the ±4 × VREF range and ±2 × VREF
range. The AD7656A also contains an on-chip 2.5 V reference.
Multifunction pin names may be referenced by their relevant
function only.
PRODUCT HIGHLIGHTS
1. Six 16-bit, 250 kSPS ADCs on board.
2. Six true bipolar, high impedance analog inputs.
3. Parallel and high speed serial interfaces.
1 _{Protected by U.S. Patent No. 6,731,232.}
Rev. 0
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