Trimmer vs digital potentiometer?

[asrock70]

In the device I have an SMD trimmer 3x3mm 10k 5% linear, +5V working frequency in the order of kHz, .
Used to set the operating point during calibration.
Sets the current in the order of 400uA to 4000uA .
The device is calibrated for a normal room temperature of 25C.
If the temperature is more or 10C higher or lower, it is already reflected in the dynamic accuracy of the device, the error of 1.5% and especially the range of applicability, decreases or increases by up to 10% .
It usually doesn't matter, but I'm still considering the possibility of enabling self-calibration in the new version.

This means adding a differential amplifier something like the INA145 and replacing the mechanical trim with a digital potentiometer any as AD5160.

That brings us to the questions
If I use a digital potentiometer, will any parameters deteriorate against the mechanical trimmers?

Whether dynamic, noise, temperature stability, long-term accuracy or anything else?
Are there any digital potentiometers with a switch? In addition to the 0-10k resistor, they can be in a state of high impedance .

 

[betwixt]

Most digital potentiometers, including the AD5160 can only operate with voltages between GND and VDD on any of the analog pins so careful if your application takes any pin to a negative voltage. It also has a fairly high capacitance between the potentiometer pins and ground, higher than a conventional pot. I'm not aware of any deterioration problems but you do of course have to program it each time the power is cycled so it may get reset more often than a real pot.

Brian.

 

[asrock70]

thank you for the information, the voltage at the terminals is between GND and 5V, ie between ground and the supply voltage, more precisely, between 300mV and 5V .
I have one more question about trimmers
How many positions does a classic single-turn trinner really have?
Yes, in theory it is an analog matter, but the rider has some dimensions and so he should have some minimal step as with the digital
10k 8bit digitl trimmer have LBS about 40Ohm

 

[BradtheRad]

How many positions does a classic single-turn trinner really have?

A carbon-film potentiometer theoretically gives you infinitely variable adjustment.

In practice, however, we often dial it between our thumb and fingers, or use a tiny screwdriver, etc. We end up moving it back and forth trying to achieve an exact setting somewhere in between. The shaft has a bit of stiffness causing us to overshoot every attempt. Say the range of movement is 200 degrees. So call it 200 positions.