hi team:
My customer use TPS65265 device and feedback that there is no output of BUCK1/2/3. The SCH and the waveform of PVIN and EN is as below.
As i check the spec, the customer try to float the mode pin, and it works normally.
but i still not clear of the logic between Mode ,UVLO and Enable.
query:
1. i calculate the Vstart and Vstop base on the 100K and 22K, the Vstart is 6.09V, and Vstop is 5.61V. As the waveform shows ,the PVIN did not reach to the 6V, but the ENable pin already reach to 1.2V. So i think that when the PVIN is unstable ,but the EN is high, then comes with no output is reasonable.
->if i use this UVLO function when the MODE connect to the GND ,how does this UVLO setting and ENABLE/ auto power up sequence logic work? it seems that the PVIN is more delay than the EN.
->when floating the Mode pin, the buck 1/2/3 output normally, if there any restriction to block the timing ? or it will ignore the setting of UVLO?