One MCU is connected to BQ76PL455 for communication. After wake-up, the 24 V power supply will source 7mA current with VP 3.3V. After initialization, the TX pin send out signal without distortion. And the receiver signal of BQ76PL455 is without distortion either. The VIO and WAKEUP is powered by 3.3V. VP and VDIG is powered by 5.3V. The VREF pin is 2.5V. CHP-CHM generates a square wave with 3us period. The RX and TX pin are pulled up by 10k resistor placed near the BQ76PL455 with 100 ohm serial resistors
Through the oscilloscope, when the MCU send require signal per 500ms, The BQ76PL455 will reply per several seconds(sometimes per 10 seconds). And now, I can not get the reply signal anymore.
