FUNCTIONAL BLOCK DIAGRAM

a

Complete 8-Bit

A-to-D Converter

AD570*

FEATURES

Complete A/D Converter with Reference and Clock

Fast Successive Approximation Conversion: 25

s

No Missing Codes Over Temperature

0 C to +70 C: AD570J

–55 C to +125 C: AD570S

Digital Multiplexing: Three-State Outputs

18-Pin Ceramic DIP

Low Cost Monolithic Construction

PRODUCT DESCRIPTION

The AD570 is an 8-bit successive approximation A/D converter

consisting of a DAC, voltage reference, clock, comparator, suc-

cessive approximation register and output buffers—all fabricated

on a single chip. No external components are required to per-

form a full accuracy 8-bit conversion in 25

µs.

The AD570 incorporates the most advanced integrated circuit

design and processing technology available today. I

grated injection logic) processing in the fabrication of the SAR

function along with laser trimming of the high stability SiCr

thin-film resistor ladder network at the wafer stage (LWT) and a

temperature compensated, subsurface Zener reference insures

full 8-bit accuracy at low cost.

Operating on supplies of +5 V and –15 V, the AD570 accepts

analog inputs of 0 V to +10 V unipolar of

±5 V bipolar, exter-

nally selectable. As the BLANK and CONVERT input is driven

low, the three-state outputs go into the high impedance state

and a conversion commences. Upon completion of the conver-

sion, the DATA READY line goes low and the data appears at

the output. Pulling the BLANK and CONVERT input high

three states the outputs and readies the device for the next con-

version. The AD570 executes a true 8-bit conversion with no

missing codes in approximately 25

µs.

The AD570 is available in two version; the AD570J is specified

for the 0

°C to +70°C temperature range, the AD570S for –55°C

to +125

°C. Both guarantee full 8-bit accuracy and no missing

codes over their respective temperature ranges.

*U.S. Patents Numbered: 3,940,760; 4,213,806 and 4,136,349.

REV. A

Information furnished by Analog Devices is believed to be accurate and

reliable. However, no responsibility is assumed by Analog Devices for its

use, nor for any infringements of patents or other rights of third parties

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703

PRODUCT HIGHLIGHTS

1. The AD570 is a complete 8-bit A/D converter. No external

components are required to perform a conversion. Full-scale

calibration accuracy of

±0.8% (2 LSB of 8 bits) is achieved

without external trims.

2. The AD570 is a single chip device employing the most ad-

vanced IC processing techniques. Thus, the user has at his

disposal a truly precision component with the reliability and

low cost inherent in monolithic construction,

3. The AD570 accepts either unipolar (0 V to +10 V) or bipolar

(–5 V to +5 V) analog inputs by grounding or opening a

single pin.

4. The device offers true 8-bit accuracy and exhibits no missing

codes over its entire operating temperature range.

5. Operation is guaranteed with –15 V and +5 V supplies. The

device will also operate with a –12 V supply.

6. The AD570S is also available processed to MIL-STD-883C,

Class B. The military data sheet for the AD570SD/883B is

included in the Analog Devices Military Products Databook.