AnsweredAssumed Answered

Cold test fail

Question asked by Ahn Joseph on Nov 8, 2018
Latest reply on Nov 14, 2018 by Daniel Martynek



1. Application : Automotive HVAC 260W BLDC controller(12zvm) 

2. Issue : Cold test fail 

3. Condition : -40 degree & Input volt swing (8V<-->40V)


 When I did test my BLDC controller in chamber be setup  -40 degree and input Volt swing 8<---16V

 DC Input change 8V to 16 V then that happen Desaturation Err but 16V to 8V is no problem  


Err condition temperature is changed by Bootstrap cap value (Please Ref, parts" C23" on circuit)

Desaturation Err is dependent (Please Ref below data)

   1. 220uF: -7`C

  1. 320uF : -25`c
  2. 470uF : -27`c
  3. 570uF : -30`c
  4. 690uF : -1`c


I had tried volt change with slop then it case is no problem 


Can you advise to me ?

I had update my circuit & Oscilloscope capture data  (Yellow : High side PWM / Blue : Current of DC power line)