Hello,
I am working on a new application with the MC33816. The injectors are not firing. I see that I have an over_temp fault in the Driver_config register. When I measure the IC with a thermal camera, it appears to only be 40 deg C. Is it possible I may have caused damage to the IC somehow? Would you recommend replacing the IC, or check elsewhere first?
Thanks,
Robert
I have replaced the IC, and the same issue occurs. We have a previous rev PCB that worked fine. There are two principal changes made regarding the MC33816. The VCCP is now supplied with an external regulator. Also, caps were added to VCC2P5. I have image below.
I can confirm VCCP is 7.1V.
Some other changes are in reducing noise in VBOOST circuit, which appears to be working just fine.
If you change VCCP from LDO into external power supply, does this issue disappear?
You can change new one to test again,if still has issue please share with your schematic.
I noticed that the boost converter switching FET is being switched at 550 kHz (roughly). The data sheet calls out a frequency range of 100-300 kHz. How is this frequency defined? Is this perhaps related?
Yes the Boost switch frequency is abnormal,what's the output of boost?