Hello,
I am trying to use a DRV592 to drive a TEC module and getting too little voltage. The inputs are PWM outputs of an Atmel 328p at 1kHz. The impedance of the TEC module is ~265 mOhm and the TEC data sheet calls for 1.8V at up to 6A (but I only need 1-2 A). Looking at the output across the TEC on a scope I see voltage pulses of only about 200 mV. The pulse width changes with the input, so that seems to be ok.
When I look at the beginning output pulse on a short time scale, I see that there is a large spike followed by ringing with a period of around 1 microsecond. That is much faster than the input pulses (1 kHz). I see the ringing with and without the low pass filters on the output. I am using the components for the filters from the datasheet, even though my input pulses are much lower than 500 kHz. What could the problem be?
Thanks