TPS53219A: waveform check

GARETH OU 

The initial spike on the rising edge of the switching node appears to be high, suggesting that that Power Input bypassing could be improved, or a snubber used, and the spike amplitude should be compared against the break-down voltage rating of the low-side FET, and the output voltage ripple suggests that there may be a 1MHz inter-capacitance resonant frequency, but I do not see anything particularly bad about the waveforms, just a few minor improvements that could be made.

GARETH OU 

As I pointed out in my prior e-mail, there appears to be an approximately 1MHz inter-capacitance resonance in the output capacitor bank.  The ESL and layout inductance between two ceramic capacitors of different values is creating a resonant tank.  This is not uncommon when smaller capacitors with 10:1 capacitance ratio are used to lower the output impedance at high frequency.  For 1MHz, a common capacitor pair would be 10uF and 1.0uF.

If the small amount of 1MHz ripple needs to be suppressed, you can try adding a 3.3uF capacitor between the 10uF and 1.0uF to reduce the impedance in between the two capacitors self-resonance frequencies.

GARETH OU 

You are welcome.  I am closing out this thread as resolved.  If you have additional question, please create a new thread.