AD1385

REV. 0

–15–

Figure 28. Basic AD1385 Digital Interface (16-Bit Complementary 2s Complement Data,

Autozero Not Used, Other Digital and Analog Inputs Not Shown)

The layout accommodates buffer amplifiers with standard op

amp pinouts in both 14- and 8-pin DIP packages. The pin

numbers shown for U12 in Figure 29 refer to the 14-pin format.

An 8-pin op amp such as the AD845 should be positioned with

package Pin 4 inserted in layout Pin 6. The AD845 provides

slightly better distortion performance than the AD842, an am-

plifier in a 14-pin package, with no significant increase in noise.

Sample Board Layout

Figures 29-34 show the layout of an evaluation board for the

AD1385. This layout incorporates the grounding, power distri-

bution, and interface concepts described in previous sections.

This 4-layer layout makes extensive use of ground and power

planes and provides optimal AD1385 performance.