Hi,
I'm trying to understand how the DRV594 works in Heating mode.
According to the datasheet, the output voltage will increase (in the -ve direction, hence more heating) as the differential input voltage (Vin+ - Vin-) gets closer to 0.
That's opposite of how the cooling mode works, in which the output voltage is proportional to differential input voltage - as the difference grows in the positive direction, the voltage at the load is higher (more cooling)
In this case, my VDD is 5V, and Vin- is my Vref which is approx 2.05 Volts.
Plotting the equations for heating and cooling in the datasheet, the response I get is shown in the picture below.
This is counterintuitive as I expected the output voltage to be linear - the more negative the differential input is, the more heating, and the more positive the differential voltage is, the more cooling.
Please let me know if i'm misinterpreting the datasheet, or if the input to the driver needs to take this discontinuity into account.
Thanks,
Mohammed