9

LTC1655

A Wide Swing, Bipolar Output 16-Bit DAC

This circuit shows how to make a bipolar output 16-bit

DAC with a wide output swing using an LTC1655 and an

LT1077. R1 and R2 resistively divide down the LTC1655

output and an offset is summed in using the LTC1655

onboard 2.048V reference and R3 and R4. R5 ensures that

the onboard reference is always sourcing current and

scale. The LT1077 output will have a wide bipolar output

swing of – 4.096V to 4.096V as shown in the figure below.

With this output swing 1LSB = 125

µV.

CLK

CS/LD

µP

0.1

µF

GND

R1

100k

1%

5V

LTC1655

1655 TA05

–

+

LT1077

5V

–5V

R2

200k

1%

R3

100k

1%

R5

100k

1%

R4

200k

1%

65536

4.096

– 4.096

32768

0

65535

TRANSFER CURVE

– 4.096V