Digital Potentiometers

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13

Offset Voltage and Gain Adjustment

Connect the high and low terminals of one potentiome-

ter of a MAX5477 between the NULL inputs of a

MAX410 and the wiper to the op amp’s positive supply

to nullify the offset voltage over the operating tempera-

ture range. Install the other potentiometer in the feed-

back path to adjust the gain of the MAX410 (Figure 12).

Adjustable Voltage Reference

Figure 13 shows the MAX5477/MAX5478/MAX5479

used as the feedback resistors in multiple adjustable

voltage reference applications. Independently adjust

the output voltages of the MAX6160 parts from 1.23V to

MAX5477/MAX5478/MAX5479.

MAX6160

IN

5V

OUT

ADJ

GND

HA

LA

WA

VOUT1

IN

OUT

ADJ

GND

HB

LB

WB

1/2 MAX5477

1/2 MAX5478

1/2 MAX5479

MAX6160

1/2 MAX5477

1/2 MAX5478

1/2 MAX5479

FOR THE MAX5477

10k

Ω

R

FOR THE MAX5478

50k

Ω

R

FOR THE MAX5479

100k

Ω

R

AND D = DECIMAL VALUE OF WIPER CODE

RR

Figure 13. Adjustable Voltage Reference

3

2

5V

7

4

1

6

8

MAX410

HA

LA

WA

R2

R1

HB

LB

WB

1/2 MAX5477

1/2 MAX5477

AND = D DECIMAL VALUE OF WIPER CODE

Figure 12. Offset Voltage Adjustment Circuit

MAX5477

MAX5478

MAX5479

HB

WB

LB

HA

WA

LA

C

MAX410

V+

V-

AND D = DECIMAL VALUE OF WIPER CODE

Figure 11. Programmable Filter

16

1

2

3

4

12

11

10

9

15

14

13

56

7

8

N.C.

HA

WA

LA

HB

WB

LB

WP

SCL

SDA

A0

A1

A2

GND

N.C.

TOP VIEW

MAX5477

MAX5478

MAX5479

14

13

12

11

10

9

8

1

2

3

4

5

6

7

SCL

SDA

A0

HB

LA

WA

HA

A1

A2

GND

WP

LB

WB

TSSOP

(4.4mm x 5mm)

THIN QFN

(3mm x 3mm)

MAX5477

MAX5478

MAX5479

Pin Configurations

Chip Information

TRANSISTOR COUNT: 12,651

PROCESS: BiCMOS