Part Number: AM3358 Hi, I designed the board using "AM3358BZCZ100", but the product behaves differently at power on. Of the five, there are some that start normally, some that start occasionally, and some that do not start at all. The cause is that the “LDO1 pin(1.8V)” of “ TPS65218D0 ” transiently rises to 2 V when the power is turned on. Due to this overvoltage, the power supply start-up sequence of " TPS65218D0 " stops halfway. In order to investigate the cause, I removed the load of "LDO1" from group 1 to 3 in order. LDO1 connect group (group1) analog circuits load = 100uA VDDA_ADC VREF_P (group2) VDDS VDDS_SRAM_CORE_BG VDDS_SRAM_MPU_BB VDDS_RTC (group3) VDDS_PLL_CORE_LD VDDS_PLL_MPU VDDS_PLL_DDR VDDS_OSC When group 3 was removed, it now works properly. It seems that an overvoltage will be applied from the “AM3358BZCZ100 PLL,OSC” terminal to the “LDO1” when the power is turned on for some reason. By adding a 500 ohm resistor as a load to the “LDO1” terminal, the overvoltage does not appear. Is it the characteristic of "AM3358BZCZ100"? Is there a problem with using "AM3358BZCZ100"? Regards, Isao.
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