Other Parts Discussed in Thread: TPS54160
Hi, TI Support Team
Yesterday I tested the TPS54160 on PMLKBUCK EVM and nothing went wrong.
However, today when I test the TPS54160 on PMLKBUCK EVM, the output voltage keeps on about 1.5V, which should be 3.3 V in this design.
When I debugging this EVM, I found that when the power supply is on and the load is off, the switching frequency seems to be 30kHz and when I short the Clock PIN it becomes 60kHz, of which the frequency is designed to be 250kHz and 500kHz respectively.
I have two same EVM, with the same pin setup conditions, I find that in the new EVM, there should not be any waveforms while in this broken EVM, there is a strange waveforms with high inductor current.
I wonder know what's going on that causes this problem, because I don't do anything after yesterdays work while this EVM seems to be broken.
Here is the waveforms that I test in the broken EVM, of which CH1 is the output voltage ripple, CH2 is the inductor current and CH3 is the switching node, the input voltage is 0.6V and the input current is 0.5-0.6A, the load is off.
in the EVM, the J13-J15 is shorted, J17 is shorted and the other pin is all open.
Thanks for your support.