Other Parts Discussed in Thread: TMS320F280039C, UCC27444, CD4010B,
Tool/software:
I am using CD4504BM96 Hex level shifter for TTL to CMOS level shifting of PWM signals (3.3V to 12V).
The PWM pins of controller TMS320F280039C are directly connected to above said level shifter.
With above level shifter we are facing issue that during power up condition IC is generating High pulse at output.
Output waveform attached for reference. In the attached waveform (TI level shifter.jpg)
CH1 (Yellow): 12V supply to Level shifter(VDD)
CH2 (Blue): Output signal of Level shifter
Ch3 (Red): 5V supply to level shifter(VCC)
Ch4(Green): 3.3V to controller
From the waveform it is observed that CD4504BM96 generate output pulse when 12V signal is above 2V but 5V supply is below 1.6V.
When 5V supply reaches above 1.6V output is again 0V. No action from controller side as 3.3V is at 0V.
How to avoid such pulse during power ON condition. As this pulse turning all Power MOSFET ON at same time resulting short in power circuit.
