I am trying to stabilize the temperature of a LASER diode mount (Thorlabs LDM21) using ADN8831-EVALZ. Below given are the TEC and Thermistor specs:
Max TEC Current = 2.5A
Max TEC voltage = 1.8V
TEC Heating/Cooling Capacity = 2W
10 kΩ NTC Thermistor
I have not connected the LASER yet, I am testing the TEC module only. The ambient temperature is kept at 25 degrees Celsius.
The board is not able to stabilize the temperature of the mount. The Voltage at TEMPOUT pin varies between 0.90V to 1.70V periodically. The TEMP GOOD LED glows periodically and for a split second whenever it crosses 1.25V on TEMPOUT pin.
What could be the reason of such a behavior?