AD5171BRJZ5-R2 datasheet(15/24 Pages) AD

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AD5171

Rev. D | Page 15 of 24

TERMINAL VOLTAGE OPERATING RANGE

POWER-UP/POWER-DOWN SEQUENCES

There are also ESD protection diodes between VDD and the

RDAC terminals; therefore, the VDD of the AD5171 defines their

voltage boundary conditions (see Figure 31). Supply signals

present on Terminal A, Terminal B, and Terminal W that

exceed VDD are clamped by the internal forward-biased diodes

and should be avoided.

Similarly, because of the ESD protection diodes, it is important

to power VDD first before applying any voltages to Terminal A,

Terminal B, and Terminal W. Otherwise, the diode is forward-

biased such that VDD is powered unintentionally and can affect

the remainder of the users’ circuits. The ideal power-up sequence is

the following order: GND, VDD, digital inputs, and VA/VB/VW.

The order of powering VA, VB, VW, and the digital inputs is not

important as long as they are powered after VDD. Similarly, VDD

should be powered down last.

GND

VDD

Figure 31. Maximum Terminal Voltages Set by VDD

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