AD5165

Rev. 0 | Page 15 of 16

LAYOUT AND POWER SUPPLY BYPASSING

It is good practice to employ compact, minimum lead length

layout design. The leads to the inputs should be as direct as

possible with a minimum conductor length. Ground paths

should have low resistance and low inductance.

Similarly, it is also good practice to bypass the power supplies

with quality capacitors for optimum stability. Supply leads to

the device should be bypassed with disk or chip ceramic

capacitors of 0.01 µF to 0.1 µF. Low ESR 1 µF to 10 µF tantalum

or electrolytic capacitors should also be applied at the supplies

to minimize any transient disturbance and low frequency ripple

(see Figure 42). Note that the digital ground should also be

joined remotely to the analog ground at one point to minimize

the ground bounce.

GND

C3

10

µF

C1

0.1

µF

AD5165

+

Figure 42. Power Supply Bypassing

EVALUATION BOARD

An evaluation board, along with all necessary software, is

available to program the AD5165 from any PC running

Windows® 98/2000/XP. The graphical user interface, as shown

in Figure 43, is straightforward and easy to use. More detailed

information is available in the user manual, which comes with

the board.

Figure 43. AD5165 Evaluation Board Software

The AD5165 starts at midscale upon power-up. To increment

or decrement the resistance, the user may move the scroll bars

on the left. To write any specific value, the user should use the

bit pattern in the upper screen and click the Run button. The

format of writing data to the device is shown in Figure 32.