AD5116 datasheet(21/24 Pages) AD

21 / 24 page

Data Sheet

AD5111/AD5113/AD5115

Rev. 0 | Page 21 of 24

POWER-UP SEQUENCE

Because of the ESD protection diodes that limit the voltage

compliance at the A, B, and W terminals (see Figure 45), it is

important to power on VDD before applying any voltage to the

A, B, and W terminals. Otherwise, the diodes are forward-

biased such that VDD is powered on unintentionally and can

affect other parts of the circuit. Similarly, VDD should be

powered down last. The ideal power-on sequence is in the

following order: GND, VDD, and VA/VB/VW. The order of

powering VA, VB, VW and the digital inputs is not important as

long as they are powered on after VDD.

GND

VDD

Figure 45. Maximum Terminal Voltages Set by VDD and GND

LAYOUT AND POWER SUPPLY BIASING

It is always a good practice to use compact, minimum lead

length layout design. The leads to the input should be as direct

as possible with a minimum conductor length. Ground paths

should have low resistance and low inductance. It is also good

practice to bypass the power supplies with quality capacitors.

Apply low equivalent series resistance (ESR) 1 μF to 10 μF

tantalum or electrolytic capacitors at the supplies to minimize

any transient disturbance and to filter low frequency ripple.

Figure 46 illustrates the basic supply bypassing configuration

for the AD5111/AD5113/AD5115.

VDD

GND

0.1µF

10µF

AGND

AD5111/

AD5113/

AD5115

Figure 46. Power Supply Bypassing

AD5116 Datasheet(PDF) 21 Page - Analog Devices