Other Parts Discussed in Thread: AM6422
Hi,
We are using TPS6521903 to supply power for AM6422, but TPS6521903 can't power up normally when serdes refclk is provided to AM6422, the DC/DC and LDO outputs of TPS6521903 can only be turned on for 100 mS, then shut down, please refer to below waveform. After disconnect the serdes refclk to AM6422(remove R3789&R381 in our schematics) or disconnect the power supplied to VDDA_0P85_SERDES0 of AM6422(remove L6 in our schematics), TPS6521903 can power up normally, each DC/DC and LDO can get the expected output voltage. It looks there is current leackage path from AM6422 serdes refclk to its VDDA_0P85_SERDES0, then impact TPS6521903 ldo2(VDDAR_CORE) and cause TPS6521903 to be latched up during power up, please help review our schematics to check any incorrecct design to cause such problem, thanks
ch1 is buck1(VDD_CORE), ch2 is ldo2(VDDAR_CORE), ch3 is gpo2(VCC_3V3_SYS_EN)
ch1 is buck1(VDD_CORE), ch2 is ldo2(VDDAR_CORE), ch3 is serdes_refclk(to AM6422 pin W17))
ch3 is serdes refclk to AM6422
Regards,
ji-xiong wu
