Post Go back to editing

digital potmeter performance

Category: Hardware
Product Number: AD5293

Hello everyone,

I am working with the digital potmeter AD5293.

I am ble to program it and vary the wiper value.

I set up the potmeter so that the terminal A is connected to a square wave 0-5.15V, the terminal b is connected to ground and the wiper is measured with oscillsocope.

Practically a voltage divider with a square wave generator instead of a constant power supply.

the measurement of the wiper voltage are shown below: when dig potmeter is set to 250 value

near the expected value, so OK.

when i se the dig potmeter to 750 value.

I also get reasonable waveform

However, when I set the potmeter to 500 value.

I can see a non linearity occurring during the rising edge of the waveform.

It seems that when the wiper is near the middle of the possible range then this non linearity appear.

Does anyone know why? or can someone point out which part of the datasheet describes this behaviour?

  • just wanted to add that the connection around the potmeter that I used

    the wiper is connected to a voltage buffer implemented with Ad8610 but I already checked that the behaviour is the same with or without the buffer connected.

    I also measured the waveform created by the inverter connected to RH terminal of AD5293. The waveform is a nice square wave with no non liearities