REV. F

AD587

–7–

NEGATIVE REFERENCE VOLTAGE FROM AN AD587

The AD587 can be used to provide a precision –10.000 V output

supply, the output pin is grounded, and the AD587 ground pin is

output is now taken from the ground pin (Pin 4) instead of

2.5 mA and 10.0 mA. The temperature characteristics and long-

term stability of the device will be essentially the same as that of

a unit used in the standard +10 V output configuration.

2

6

4

GND

AD587

3.5V

→

→26V

1nF

–15V

–10V

2.5mA <

5V

Figure 11. AD587 as a Negative 10 V Reference

USING THE AD587 WITH CONVERTERS

The AD587 is an ideal reference for a wide variety of 8-, 12-,

14-, and 16-bit ADCs and DACs. Several representative examples

follow.

10 V Reference with Multiplying CMOS DACs or ADCs

The AD587 is ideal for applications with 10-bit and 12-bit

multiplying CMOS DACs. In the standard hookup, as shown in

Figure 12, the AD587 is paired with the AD7545 12-bit multi-

plying DAC and the AD711 high speed BiFET op amp. The

amplifier DAC configuration produces a unipolar 0 V to –10 V

output range. Bipolar output applications and other operating

details can be found in the individual product data sheets.

AD587

GND

AD711K

0.1 F

–15V

0 TO

0.1 F

+15V

OUT1

AGND

DGND

DB11–DB0

C1

33pF

R2

+15V

AD7545K

10k

TRIM

+15V

0.1 F

Figure 12. Low Power 12-Bit CMOS DAC Application

The AD587 can also be used as a precision reference for multi-

ple DACs. Figure 13 shows the AD587, the AD7628 dual DAC,

and the AD712 dual op amp hooked up for single-supply opera-

tion to produce 0 V to –10 V outputs. Because both DACs are

on the same die and share a common reference and output

op amps, the DAC outputs will exhibit similar gain TCs.

0 TO – 10V

AD587

GND

AD712

+15V

OUT A

DGND

+15V

AGND

DAC A

DB0

DB7

DATA

INPUTS

OUT B

DAC B

18

RFB B

RFB A

0 TO – 10V

AD7628

0.1 F

Figure 13. AD587 as a 10 V Reference for a CMOS Dual DAC

Precision Current Source

The design of the AD587 allows it to be easily configured as a

the user can vary the load current from the quiescent current

(2 mA typically) to approximately 10 mA.

2

6

4

GND

AD587

500

MIN

10V

Figure 14. Precision Current Source