AD7524M

Advanced LinCMOS

™ 8-BIT MULTIPLYING

DIGITAL-TO-ANALOG CONVERTER

SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995

6

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

REF

OUT2

OUT1

RFB

R

120 pF

30 pF

I1kg

1/256

I1kg

Figure 1. AD7524M Equivalent Circuit With All Digital Inputs Low

+

–

Output

RA = 2 kΩ

(see Note A)

WR

CS

DB0 – DB7

Vref

C (see Note B)

RB

VDD

GND

OUT2

OUT1

RFB

Figure 2. Unipolar Operation (2-Quadrant Multiplication)

20 k

Ω

–

+

+

–

20 k

Ω

5 k

Ω

10 k

Ω

RA = 2 kΩ

(see Note A)

Output

WR

CS

DB0 – DB7

Vref

C (see Note B)

RB

VDD

GND

OUT2

OUT1

RFB

Figure 3. Bipolar Operation (4-Quadrant Operation)

NOTES: A. RA and RB used only if gain adjustment is required.

B. C phase compensation (10 – 15 pF) is required when using high-speed amplifiers to prevent ringing or oscillation.