TLV62569: TLV62569 Used as 5V to 3.3V ,When the load at 420ma ,the ripple of 3.3V is very high（140mVpp）then test SW pin ,SW PIN show is switch at PWM and PFM mode ,the ash as below ,When i set L16 2.2uH to 1uH,The ripple down to 270mA,the swing of work mod

HI Andrew,

It is not very clear to me, could you clarify this sentence : "When i set L16 2.2uH to 1uH,The ripple down to 270mA,"
Could you clarify the operating conditions for "waveform 1" and "waveform 2"? VIN, Vout, Iout and any BOM change from the schematic you posted

Dear Sabrina ,1/ when i change the L16 in sch , from 2.2uH to 1uH, Vin 5V, Vout= 3.3V/420mA , Voutput ' ripple change from 144mVpp to 26.4mVpp.
2/I change the L16 in sch , from 2.2uH to 1uH. 

what is the resaon ? if there any hidden trouble ?

Hi Andrew,
This is the way the device works, as you can see in Fig 15 of the datasheet, the ripple in PFM mode is in the range 0f 100mV. and when it operates in PWM mode the Vout ripple is in the range of 10mV.

420 mA seems at the limit where the device change operation between PFM and PWM mode, therefor when the device switches between PFM and PWM mode, the Vout ripple changes accordingly.

One way of mitigating it is to reduce the inductor as you did to move the PFM entry point. or increase the output capacitor to reduce the ripple(Table 4 of DS). In the second waveform the device is operating in PWM mode which has the low ripple.