The issue is as described in the subject line:
1、The design parameters are as follows: the input source is 57–60 V, and the charging output is 56 V / 2 A. The ACUV pin is measured at 7.4 V and the ACOV pin at 3.4 V, which meet the operating conditions.
2、An external 12 V is supplied to the DRV_SUP pin, but it was confirmed that there is no voltage output at the REGN pin.
3、The /CE pin is connected to ground in the circuit, and the EN_CHG bit in the register is enabled, but there is still no output.
4、The I²C communication is functioning properly.
The schematic and register configuration parameters are attached. Could you please help advise how I can troubleshoot the issue?
* Created: Mon Oct 13 16:27:56 CST 2025 * * Format: Register Name tab Character,\t Register Address tab Character,\t Hexadecimal register value. * Device: BQ25756 * BQZ Container: Charger_1_00-bq25756.bqz * Charge Voltage Limit 0008 Charge Current Limit 00A0 Output Voltage Limit 0000 Input Current DPM Limit 0640 Input Voltage DPM Limit 0348 Reverse Mode Input Current Limit 0640 Reverse Mode Input Voltage Limit 03E8 Precharge Current Limit 0050 Termination Current Limit 0028 Precharge and Termination Control 0F Timer Control 0D Charger Control C9 Pin Control C0 Power Path and Reverse Mode Control 20 MPPT Control 20 TS Charging Threshold Control 96 TS Charging Region Behavior Control 57 TS Reverse Mode Threshold Control 40 Reverse Undervoltage Control 00 VAC Max Power Point Detected 0000 Charger Status 1 03 Charger Status 2 00 Charger Status 3 02 Fault Status 40 Charger Flag 1 00 Charger Flag 2 00 Fault Flag 00 Charger Mask 1 00 Charger Mask 2 00 Fault Mask 00 ADC Control 60 ADC Channel Control 02 IAC ADC - Use Field View 0000 IBAT ADC - Use Field View 0000 VAC ADC 0000 VBAT ADC 0000 TS ADC 0000 VFB ADC 0000 Gate Driver Strength Control 00 Gate Driver Dead Time Control 00 Part Information 12 Reverse Mode Battery Discharge Current 02
