This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS65251: Output drop during start up

Part Number: TPS65251

Hi, Team

My communication customer is using TPS65251-3 in their small cell products. They find the output voltage will drop during startup, if the outpu voltage is set to > 3.5V.

Here is customer schematic. The CH3 of TPS65251 is 5V output, and there is drop during start up. Increasing SS3capacitor C1113, or increasing COMP3 capacitor C1146, or decreasing COMP3 resistor R1021 can not help.

Is there any suggestion to solve the issue?

Here is is waveform:

(1)

CH1: Input Voltage

CH3: Output Voltage, there is a drop when output rise to about 4V.

(2)

CH1: LX3

CH3: Output Voltage, there is a drop when output rise to about 4V.

(3)

CH1: LX3

CH3: Output Voltage, there is a drop when output rise to about 4V.

(4)

CH1: LX3

CH3: Output Voltage, there is a drop when output rise to about 4V.

Thanks

Kevin