TPS61150A: PWM Signal

Hi Mason,

    I don't understand your question clearly. Could you share us the schematic that you tested with above question? 

Regards

Sean

Hi sir,

    What's your input voltage for this test?

    Please remove R284 and R113 since there are pull-down resistor in the device.

   What's your test process when you observed the voltage drop?

    What's your meaning of "If SEL1 and SEL2 are connected and one signal is applied, there is no voltage drop."

Regards

Sean

Hi Mason,

     How about the phase between the two PWM signals when you do the independent test?

     And have you measure the output current of each channel when you do the independent test and together test? Have you found any current change when you do the test?

     Since for our LED driver, what we want to do is to make the output current constant and there may some voltage transient since you are using PWM dimming, but if the output current keeps no change, that's ok.

Regards

Sean

Hi Mason,

    No, the phase is not important, have you checked the output current? Is that correct when you change the phase between those two PWM signals?

Regards

Sean

Hi mason,

    That depends on the output impedance of the PWM signal pins, it may affect the signal amplitudes, but I also suggest you to measure the output current with different PWM signal connection.

Regards

Sean