Differential Input,Dual,Simultaneous
Sampling, 4.25 MSPS, 14-Bit, SAR ADC
AD7357
Preliminary Technical Data
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Vdrive
Vdd
Dual 14-bit SAR ADC
Simultaneous Sampling
AD7357
Throughput rate: 4.25 MSPS Per Channel
Specified for VDD of 2.5 V
Power dissipation:
14-BIT
SUCCESSIVE
APPROXIMATION
ADC
V
V
IN
A+
A-
SDATA
A
T/H
IN
35 mW at 4.25 MSPS
On-chip reference:
BUF
BUF
2.048 V 0.5% max @ 25°C, 10ppm/°C
Dual conversion with read
High speed serial interface:
SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible
−40°C to +125°C operation
Shutdown mode: 10 µA max
16-lead TSSOP package
SCLK
CS
CONTROL
LOGIC
REF
14-BIT
SUCCESSIVE
APPROXIMATION
ADC
V
IN
B+
T/H
V
IN
B-
SDATA
B
AGND
REFGND
AGND
DGND
Figure 1.
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD73571 is a dual, 14-bit, high speed, low power, successive
approximation ADC that operates from a single 2.5 V power supply
and features throughput rates up to 4.25 MSPS. The part contains
two ADCs, each preceded by a low noise, wide bandwidth track-
and-hold circuit that can handle input frequencies in excess of
200 MHz.
1. Two Complete ADC Functions Allow Simultaneous Sampling
and Conversion of Two Channels.
The conversion result of both channels is simultaneously
available on separate data lines or in succession on one data
line if only one serial port is available.
2. High Throughput with Low Power Consumption.
The AD7357 offers a 4.25 MSPS throughput rate with 35 mW
power consumption.
The conversion process and data acquisition use standard control
inputs allowing for easy interfacing to microprocessors or DSPs.
CS
The input signal is sampled on the falling edge of ; conversion is
also initiated at this point. The conversion time is determined by
the SCLK frequency.
3. The part features two standard successive approximation
ADCs with accurate control of the sampling instant via a
The AD7357 uses advanced design techniques to achieve very low
power dissipation at high throughput rates. With 2.5 V supply and
a 4.25 MSPS throughput rate, the part consumes 14 mA typically.
The part also offers flexible power/throughput rate management
when operating in normal mode as the quiescent current
consumption is so low.
CS
input and once off conversion control.
1 Protected by U.S. Patent No. 6,681,332
Table 1: Related Devices.
Generic
AD7356
AD7352
Resolution
Throughput Analog Input
12
12
5MSPS
3MSPS
Differential
Differential
The analog input range for the part is the differential common
mode +/- Vref/2. The AD7357 has an on-chip 2.048 V reference
that can be overdriven when an external reference is preferred.
The AD7357 is available in a 16-lead thin shrink small outline
package (TSSOP).
Rev. PrD
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