®
ADC774
Microprocessor-Compatible
ANALOG-TO-DIGITAL CONVERTER
FEATURES
q
COMPLETE 12-BIT A/D CONVERTER WITH
REFERENCE, CLOCK, AND 8-, 12-, or 16-
BIT MICROPROCESSOR BUS INTERFACE
q
ALTERNATE SOURCE FOR HI774 A/D
CONVERTER: 8.5
µ
s Conversion Time,
150ns Bus Access Time
q
FULLY SPECIFIED FOR OPERATION ON
±
12V OR
±
15V SUPPLIES
q
NO MISSING CODES OVER
TEMPERATURE:
0
°
C to +75
°
C: ADC774J, K
–55
°
C to +125
°
C: ADC774SH, TH
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 8.5µs 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 ADC774, 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, or a hermetic side-brazed ceramic DIP.
DESCRIPTION
The ADC774 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-
Control
Inputs
Control Logic
Status
Bipolar
Offset
20V Range
Clock
Successive
Approximation
Register
10V Range
Reference
Input
Reference
Output
Comparator
12-Bit D/A
Converter
10V
Reference
Three-State Buffers
Parallel
Data
Output
International Airport Industrial Park • Mailing Address: PO Box 11400
Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP •
© 1988 Burr-Brown Corporation
• Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706
Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
PDS-835E
Printed in U.S.A. March, 1992
BURR-BROWN [ BURR-BROWN CORPORATION ]
