®
ADC574A
FPO
Microprocessor-Compatible
ANALOG-TO-DIGITAL CONVERTER
FEATURES
l COMPLETE 12-BIT A/D CONVERTER WITH
REFERENCE, CLOCK, AND 8-, 12-, or 16-
BIT MICROPROCESSOR BUS INTERFACE
l IMPROVED PERFORMANCE SECOND
SOURCE FOR 574A-TYPE A/D
CONVERTERS
Conversion Time: 25µs max
Bus Access Time: 150ns max
A
O

Input: Bus Contention During Read
Operation Eliminated
l DUAL IN-LINE PLASTIC, PLCC AND
HERMETIC CERAMIC
l FULLY SPECIFIED FOR OPERATION ON
±12V OR ±15V SUPPLIES
l NO MISSING CODES OVER
TEMPERATURE:
0°C to +75°C: ADC574AJ and K Grades
–55°C to +125°C: ADC574ASH, TH
DESCRIPTION
The ADC574A is a 12-bit successive approximation
analog-to-digital converter, utilizing state-of-the-art
CMOS and laser-trimmed bipolar die custom-designed
for freedom from latch-up and for optimum AC per-
formance. It is complete with a self-contained +10V
reference, internal clock, digital interface for micropro-
cessor control, and three-state outputs.
The reference circuit, containing a buried zener, is laser-
trimmed for minimum temperature coefficient. The
clock oscillator is current-controlled for excellent sta-
bility over temperature. Full-scale and offset errors may
be externally trimmed to zero. Internal scaling resistors
are provided for the selection of analog input signal
ranges of 0V to +10V, 0V to +20V, ±5V, and ±10V.
The converter may be externally programmed to pro-
vide 8- or 12-bit resolution. The conversion time for 12
bits is factory set for 25µs maximum.
Output data are available in a parallel format from TTL-
compatible three-state output buffers. Output data are
coded in straight binary for unipolar input signals and
bipolar offset binary for bipolar input signals.
The ADC574A, available in both industrial and military
temperature ranges, requires supply voltages of +5V
and ±12V or ±15V. It is packaged in a 28-pin plastic
DIP, and a hermetic side-brazed ceramic DIP.
International Airport Industrial Park • Mailing Address: PO Box 11400 • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706
Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
Successive
Approximation
Register
Control Logic
Comparator
12-Bit D/A
Converter
10V

Control
Inputs
Bipolar
Offset
20V Range
10V Range
Reference
Input
Reference
Output
Three-State Buffers
Status
Parallel
Data
Output
Clock
Reference
© 1984 Burr-Brown Corporation PDS-550G Printed in U.S.A., August, 1993