Part Number: TPS62992-Q1
I designed the above buck circuit and selected a 95.3Kohm Vset resistor according to the Vset table in the datasheet. However, the output voltage fluctuates between 0.5V and 2V, with a waveform close to a sine wave. I ruled out the possibility of incorrect resistor resistance and incorrect output capacitor capacitance, and also replaced the inductor with the recommended 10uh inductor, but the output result did not improve.
At the same time, I shorted the resistor to ground, and the output still did not match the 1.2V output specified in the datasheet.
I have a question that hasn't been resolved: why is the 1.25V Vset resistor in the table not arranged in order of magnitude? This does not conform to the voltage division formula. If the output voltage is determined by both the Vset resistor and the internal voltage division resistor, its value should be between 11k and 13.7k.
I want to know if there is a problem with my circuit design and the reason for the abnormal output voltage. Thank you.
