ADC0803, ADC0805

8-BIT ANALOG-TO-DIGITAL CONVERTERS

WITH DIFFERENTIAL INPUTS

SLAS034 – NOVEMBER 1983 – REVISED SEPTEMBER 1986

1

POST OFFICE BOX 655303

8 k

Ω Typical

Stand-Alone

National Semiconductor and Signetics

ADC0803 and ADC0805

description

The ADC0803 and ADC0805 are CMOS 8-bit, successive-approximation, analog-to-digital converters that use

a modified potentiometric (256R) ladder. These devices are designed to operate from common microprocessor

control buses with the 3-state output latches driving the data bus. The devices can be made to appear to the

microprocessor as a memory location or an I/O port. Detailed information on interfacing to most popular

microprocessors is readily available from the factory.

A differential analog voltage input allows increased common-mode rejection and offset of the zero-input analog

voltage value. Although a reference input (REF/2) is available to allow 8-bit conversion over smaller analog

voltage spans or to make use of an external reference, ratiometric conversion is possible with the REF/2 input

devices can operate with an external clock signal or with an additional resistor and capacitor, using an on-chip

clock generator.

The ADC0803C and ADC0805C are characterized for operation from 0

°C to 70°C. The ADC0803I and

ADC0805I are characterized for operation from – 40

°C to 85°C.

Copyright

© 1986, Texas Instruments Incorporated

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.

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CS

RD

WR

CLK IN

INTR

IN +

IN –

ANLG GND

REF/2

DGTL GND

CLK OUT

DB0 (LSB)

DB1

DB2

DB3

DB4

DB5

DB6

DB7 (MSB)

N PACKAGE

(TOP VIEW)

DATA

OUTPUTS