Tool/software:
Hi Team,
When testing TPS40210DRCR, the driving waveform is not a square wave when unloaded,and the driving waveform is a normal square wave when loaded.
The output voltage is normal in both cases. Is this situation normal?
The waveform without load is as follows:
Hi Reed,
Thanks for using the e2e forum.
This behavior is to be expected.
Under no load conditions, the duty cycle of the PWM signal will reduce. At some point, the required duty cycle will be to small for the minimum on-time of the device, so the output voltage would start running away and the device will start pulse-skipping instead.
In this application, it looks like the device is running with minimum possible on-time, so it is close to the pulse-skipping threshold.
The device seems to be able to still run with constant frequency without skipping pulses, but due to the minimum on-time switching, the gate signal does not show the same clean square wave as with higher loads.
Best regards,
Niklas
