TPSM63610EVM: ~2.2Khz ripple at output

Hi,

Can you please confirm the schematic that you are using for this device? Is it the default EVM schematic? What device and jumpers are populated on the EVM?

Thank you,

Joshua Austria

This is the default EVM schematic. Without set to 3.3V. Mode set to fixed frequency. Switching frequency set to 2.2MHz. No other jumpers were moved from default. 

Hi Alan,

Where is the output voltage ripple being measured from? Ideally, to limit any inductance that can be introduced by the oscilloscope probes, the tip and barrel method is used on the capacitor closest to the output pin of the device. 

Additionally, can you confirm? Is the EVM set to 3 V or 3.3 V?

Thank you,

Joshua Austria

I figured out of the source of the 2.2KHz signal. It was noise coupling into the feedback node.

Can I add a "decoupling" capacitor to feedback node? I know this will probably "slow down" the feedback loop and output settling time but for our application is its ok. Are there concerns for stability by adding such capacitor?

Thanks!

Alan

Hi Alan, 

Is this coupling noise from the testing environment? Ideally the source of this would be eliminated.

Additionally, are you talking about a capacitor on feedback to ground?

Thank you,

Joshua Austria