Q: TPS62102 output ripple voltage by 595903

The TPS62102  ( the external components are the same as showing in the data sheet.) seems to be working properly with about 100 mV of ripple voltage (+/- 1.9% of  nominal voltage) with MODE set to auto.

I current : around 50mA    Input V: 8V    Output V:  3.0V  

When this device put into CFM (forced constant frequency mode) by pulling the Mode pin to Vin,  the bode plot shows that cross over frequency is at 3Khz.

It is very slow.  Is this a normal?


A: Re: INT- TPS62102 output ripple voltage by 10449

The TPS62100 datasheet provides loop gain for several circuit designs.  I expect your loop gain to match the datasheet loop gain if you operate with the same components and operating conditions.  I agree that 3kHz seems very slow. This is most likely a lab setup and measurement problem, especially if your circuit matches the datasheet circuits.  The datasheet circuits' crossovers are >10kHz.  A newer IC that will provide better performance with fewer components, smaller size, and significantly higher crossover is the TPS62110.  I suggest replacing the TPS62100 with the TPS62110 before proceeding with evaluation.