TLH5521

April 1995

ADC0852ADC0854

Multiplexed Comparator with 8-Bit Reference Divider

General Description

The ADC0852 and ADC0854 are CMOS devices that com-

bine a versatile analog input multiplexer voltage compara-

tor and an 8-bit DAC which provides the comparator’s

output as a result of a comparison between the analog input

and the DAC’s output This allows for easy implementation

of set-point on-off or ‘‘bang-bang’’ control systems with

several advantages over previous devices

The ADC0854 has a 4 input multiplexer that can be software

configured for single ended pseudo-differential and full-dif-

ferential modes of operation In addition the DAC’s refer-

ence input is brought out to allow for reduction of the span

The ADC0852 has a two input multiplexer that can be con-

figured as 2 single-ended or 1 differential input pair The

The multiplexer and 8-bit DAC are programmed via a serial

data input word Once programmed the output is updated

once each clock cycle up to a maximum clock rate of

400 kHz

Features

Y

2 or 4 channel multiplexer

Y

Differential or Single-ended input software controlled

Y

Serial digital data interface

Y

256 programmable reference voltage levels

Y

Continuous comparison after programming

Y

Fixed ratiometric or reduced span reference capability

(ADC 0854)

Key Specifications

Y

Y

Single 5V power supply

Y

Low Power 15 mW

TLH5521 – 1

FIGURE 1 ADC0854 Simplified Block Diagram (ADC0852 has 2 input channels

2 Channel and 4 Channel Pin Out

ADC0852 2-CHANNEL MUX

Dual-In-Line Package

TLH5521 – 10

Top View

AGND and COM internally connected to GND

Order Number ADC0852

See NS Package Number N08E

ADC0854 4-CHANNEL MUX

Dual-In-Line Package

TLH5521 – 11

Top View

Order Number ADC0854

See NS Package Number N14A

TRI-STATE

is a registered trademark of National Semiconductor Corporation

C1995 National Semiconductor Corporation

RRD-B30M75Printed in U S A