FUNCTIONAL BLOCK DIAGRAM

3 STATE

BUFFERS

AUTO BLANK

CONTROL

10-BIT

CURRENT

OUTPUT

DAC

5k

DATA

READY

INT.

CLOCK

10-BIT

SAR

B & C

COMPARATOR

TEMPERATURE COMPENSATED

BURIED ZENER REFERENCE

AND DAC CONTROL

13

14

15

MSB

LSB

17

16

10

11

12

BLANK &

CONVERT CONTROL

V+

V–

DIGITAL

COMMON

ANALOG

IN

ANALOG

COMMON

BIPOLAR

OFFSET

CONTROL

BIT

OUTPUTS

AD571

DATA READY

6

7

8

9

2

3

4

5

18

1

a

10-Bit A/D Converter

AD571*

FEATURES

Complete A/D Converter with Reference and Clock

Fast Successive Approximation Conversion: 40

s max

No Missing Codes Over Temperature

0 C to +70 C: AD571K

–55 C to +125 C: AD571S

Digital Multiplexing: Three-State Outputs

18-Pin Ceramic DIP

Low Cost Monolithic Construction

PRODUCT DESCRIPTION

The AD571 is an 10-bit successive approximation A/D con-

verter consisting of a DAC, voltage reference, clock, compara-

tor, successive approximation register and output buffers—all

fabricated on a single chip. No external components are re-

quired to perform a full accuracy 10-bit conversion in 40

µs.

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

AD571 will accepts analog inputs of 0 V to +10 V unipolar of

±5 V bipolar, externally selectable. When the BLANK and

CONVERT

input is driven low, the three-state outputs will be

open and a conversion will commence. Upon completion of the

conversion, the DATA READY line goes low and the data ap-

pears at the output. Pulling the BLANK and CONVERT input

high blanks the outputs and readies the device for the next con-

version. The AD571 executes a true 10-bit conversion with no

missing codes in 40

µs maximum.

The AD571 is available in two version for the 0

°C to +70°C

temperature range, the AD571J and K. The AD571S guarantees

10-bit accuracy and no missing codes from –55

°C to +125°C.

*Covered by Patent Nos. 3,940,760; 4,213,806; 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 AD571 is a complete 10-bit A/D converter. No external

components are required to perform a conversion. Full-scale

calibration accuracy of

±0.3% is achieved without external

trims.

2. The AD571 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 AD571 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 10-bit accuracy and exhibits no miss-

ing codes over its entire operating temperature range.

5. Operation is guaranteed with –15 V and +5 V or +15 V sup-

plies. The device will also operate with a –12 V supply.