FUNCTIONAL BLOCK DIAGRAM

16-BIT LATCH

16-BIT DAC

CONTROL

LOGIC

+10V REF

16-BIT LATCH

20

24

22

21

5

11

12

16

15

14

13

17

18

19

23

AD660

10k

10.05k

10k

SIN/

DB0

DB7

S

OUT

SPAN/

BIP

OFFSET

V

OUT

AGND

REF OUT

REF IN

LDAC

SER

DGND

–V

EE

+V

CC

+V

LL

1

2

3

4

LBE

CS

HBE

CLR

MSB/LSB/

DB1

UNI/BIP CLR/

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.

a

Monolithic 16-Bit

Serial/Byte DACPORT

AD660

FEATURES

Complete 16-Bit D/A Function

On-Chip Output Amplifier

On-Chip Buried Zener Voltage Reference

1 LSB Integral Linearity

15-Bit Monotonic over Temperature

Microprocessor Compatible

Serial or Byte Input

Double Buffered Latches

Fast (40 ns) Write Pulse

Asynchronous Clear (to 0 V) Function

Serial Output Pin Facilitates Daisy Chaining

Unipolar or Bipolar Output

Low Glitch: 15 nV-s

Low THD+N: 0.009%

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

Tel: 617/329-4700

Fax: 617/326-8703

PRODUCT DESCRIPTION

The AD660 DACPORT

® is a complete 16-bit monolithic D/A

converter with an on-board voltage reference, double buffered

latches and output amplifier. It is manufactured on Analog De-

vices’ BiMOS II process. This process allows the fabrication of

low power CMOS logic functions on the same chip as high pre-

cision bipolar linear circuitry.

The AD660’s architecture ensures 15-bit monotonicity over

time and temperature. Integral and differential nonlinearity is

maintained at

±0.003% max. The on-chip output amplifier pro-

vides a voltage output settling time of 10

µs to within 1/2 LSB

for a full-scale step.

The AD660 has an extremely flexible digital interface. Data can

be loaded into the AD660 in serial mode or as two 8-bit bytes.

This is made possible by two digital input pins which have dual

functions. The serial mode input format is pin selectable to be

MSB or LSB first. The serial output pin allows the user to daisy

chain several AD660s by shifting the data through the input

latch into the next DAC thus minimizing the number of control

lines required to SIN, CS and LDAC. The byte mode input for-

mat is also flexible in that the high byte or low byte data can be

loaded first. The double buffered latch structure eliminates data

skew errors and provides for simultaneous updating of DACs in

a multi-DAC system.

The AD660 is available in five grades. AN and BN versions are

specified from –40

°C to +85°C and are packaged in a 24-pin

300 mil plastic DIP. AR and BR versions are also specified from

–40

°C to +85°C and are packaged in a 24-pin SOIC. The SQ

version is packaged in a 24-pin 300 mil cerdip package and is

also available compliant to MIL-STD-883. Refer to the AD660/

883B data sheet for specifications and test conditions.

DACPORT is a registered trademark of Analog Devices, Inc.

PRODUCT HIGHLIGHTS

1. The AD660 is a complete 16-bit DAC, with a voltage refer-

ence, double buffered latches and output amplifier on a sin-

gle chip.

2. The internal buried Zener reference is laser trimmed to

10.000 volts with a

±0.1% maximum error and a tempera-

ture drift performance of

±15 ppm/°C. The reference is

available for external applications.

3. The output range of the AD660 is pin programmable and can

be set to provide a unipolar output range of 0 V to +10 V or

a bipolar output range of –10 V to +10 V. No external com-

ponents are required.

4. The AD660 is both dc and ac specified. DC specifications

include

±1 LSB INL and ±1 LSB DNL errors. AC specifi-

cations include 0.009% THD+N and 83 dB SNR.

5. The double buffered latches on the AD660 eliminate data

skew errors and allow simultaneous updating of DACs in

multi-DAC applications.

6. The CLEAR function can asynchronously set the output to

0 V regardless of whether the DAC is in unipolar or bipolar

mode.

7. The output amplifier settles within 10

µs to ±1/2 LSB for a

full-scale step and within 2.5

µs for a 1 LSB step over tem-

perature. The output glitch is typically 15 nV-s when a full-

scale step is loaded.