CCS/DRV8305: ESC gets very hot with one motor, but works great with another

Part Number:DRV8305

Tool/software: Code Composer Studio

Hi. It's around 2 months we finished our ESC design and are testing it extensively since. Several days ago we tried it with new motor and ESC got very hot (120C) while rotating the motor with no load.

ESC was designed for 30A continues load and works well and goes max to 90C under full load with this motor - www.rctigermotor.com/.../287.html

When using this motor (www.dollarhobbyz.com/.../losi-1-6-audi-r8-6ix-dynamite-fuze-1200kv-brushless-motor) it ESC heats up to 120C without any load, just spinning the motor (3A current consumption).

I use InstaSpinFOC to rotate the motors. PWM frequency is 45kHz in both cases. I do the ID procedure and change all variables and motor parameters in user.h

Also using: TMS320F28027, DRV8305, 1mOhm FETs, 22.2V LiPos

We tried many different hobby outrunner motors and it works well every time.

What can be wrong here?