Low-Power, Serial 12-Bit Sampling

ANALOG-TO-DIGITAL CONVERTER

DESCRIPTION

The ADS7812 is a low-power, single +5V supply, 12-bit

sampling analog-to-digital converter. It contains a complete

12-bit capacitor-based SAR A/D with a sample/hold, clock,

reference, and serial data interface.

The converter can be configured for a variety of input ranges

including

±10V, ±5V, 0V to 10V, and 0.5V to 4.5V. A high

impedance 0.3V to 2.8V input range is also available (input

impedance > 10M

Ω). For most input ranges, the input

voltage can swing to +16.5V or –16.5V without damage to

the converter.

A flexible SPI compatible serial interface allows data to be

synchronized to an internal or external clock. The ADS7812

is specified at a 40kHz sampling rate over the –40

°C to

+85

°C temperature range. It is available in a 0.3" DIP-16 or

an SO-16 package.

FEATURES

q 20

q SINGLE +5V SUPPLY OPERATION

q PIN-COMPATIBLE WITH 16-BIT ADS7813

q EASY-TO-USE SERIAL INTERFACE

q 0.3" DIP-16 AND SO-16

q

q 72dB min SINAD

q USES INTERNAL OR EXTERNAL

REFERENCE

q MULTIPLE INPUT RANGES

q 35mW max POWER DISSIPATION

q NO MISSING CODES

q 50

ADS7812

ADS7

812

8k

CDAC

4k

40k

20k

Internal

+2.5V Ref

Clock

EXT/INT

DATACLK

DATA

Successive Approximation Register and Control Logic

Serial

Data

Out

Comparator

Buffer

BUSY

PWRD

CONV

R1

IN

R3

IN

REF

BUF

CAP

CS

R2

IN

NOTE: (1) Actual value may vary ±30%.

APPLICATIONS

q DATA ACQUISITION SYSTEMS

q INDUSTRIAL CONTROL

q TEST EQUIPMENT

q DIGITAL SIGNAL PROCESSING

ADS7812

SBAS042A – MARCH 1997 – REVISED SEPTEMBER 2003

www.ti.com

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright © 1997-2003, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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