DRV594: Using DRV593/DRV594 as a Peltier Driver

Dear Sirs.

I am using DRV594 as sa Peltier Driver.  IN+ pin of DRV594 is controlled through the DAC module as illustrated below (see this thread as well).

I want to fine-control the current through the Peltier element in a range from 0% to 100%. The difference between IN+/IN- will be used to define the driving strength (when the difference is 0V, driving strength is 0%). What I noticed is that the current through the Peltier element (voltage across Peltier) gets saturated very fast (becoming VDD).

Is this happening because of these formulas:

Vload = D x VDD;

D = A (Vin+ - Vin-) / VDD;

A = 14.5V/V in the case of DRV594
A = 2.3V/V in the case of DRV593

Because of a high gain of 14.5V/V, the small difference between IN+/IN- inputs will lead to the max current through the Peltier element (100% strength).

If we want to have finer control then it seems that DRV593 whose gain is equal to 2.3V/V should be used. It will allow us to have a difference between Vin+ and Vin- of VDD/2.3V max. Am I right?

Are there some other differences between DRV593 and DRV594 except the gain parameter?

Thanks in advance for your time and efforts. Looking forward to reading from you.

Sincerely,

Bojan.