+5V/+3V, 13-Bit, Serial, Force/Sense DACs

with 10ppm/°C Internal Reference

18

______________________________________________________________________________________

DAC

OUT

MAX5132

MAX5133

10k

26k

FB

REF

DGND

AGND

+5V/

+3V

AC

REFERENCE

INPUT

500mVp-p

MAX495

+5V/+3V

Figure 13. External Reference with AC Components

Using an External Reference

with AC Components

The MAX5132/MAX5133 have multiplying capabilities

within the reference input voltage range specifications.

Figure 13 shows a technique for applying a sinusoidal

input to REF, where the AC signal is offset before being

applied to the reference input.

Power-Supply and Bypassing

Considerations

On power-up, the input and DAC registers are cleared

to either zero (RSTVAL = DGND) or midscale (RSTVAL

capacitor in parallel with a 0.1µF capacitor to AGND.

Minimize lead lengths to reduce lead inductance.

Layout Considerations

Digital and AC signals coupling to AGND can create

noise at the output. Connect AGND to the highest quali-

ty ground available. Use proper grounding techniques,

such as a multilayer board with a low-inductance

ground plane. Wire-wrapped boards and sockets are

not recommended. If noise becomes an issue, shield-

ing may be required.

___________________Chip Information

TRANSISTOR COUNT: 3308

SUBSTRATE CONNECTED TO AGND.