PowerFlex

This version is based on the RK805 series chips.
PMICs can effectively reduce the number of external electronic components and save PCB board area. However, PMICs often require OTP customization from manufacturers. Customized chips limit their application. Chips sold online are often leftover stock of custom chips. This project provides a way to flexibly use these chips.
This project integrates a PMIC chip, inductors and resistors/capacitors, and a microcontroller for control on a 22mm x 14mm PCB board. The output voltage and timing of the PMIC can be flexibly controlled through programming, and settings can be configured via a serial character interface.
The module output channels are as follows:

BUCK1: 0.7125V~1.45V, step=12.5mV 
BUCK2: 0.7125V-1.45V, step=12.5mV 
BUCK3: 1.35V (output voltage controlled by feedback resistor)
BUCK4: 0.8V-3.5V, step=0.1V 
LDO1: 0.8V-3.4V, step=0.1V 
LDO2: 0.8V-3.4V, step=0.1V 
LDO3: 0.8V-3.4V, step=0.1V 
OUT1: IO high/low level
OUT2: IO high/low level

The above output timing can be adjusted

LDO4: 3.3V (voltage fixed, timing cannot be controlled)

 
The output voltage and timing can be set through the serial port character interface:
The above configuration will be recorded in the MCU's built-in EEPROM.
 
Board soldering precautions:

If the two I2C bus pull-up resistors in the circuit have already been soldered, the VCCIO_3V3 pin and the MCU_3V3 pin must be temporarily shorted before burning the firmware. If the two resistors have not been soldered, the firmware can be burned directly.
If there is no requirement for the CPU/OS to dynamically adjust the PMIC output voltage according to the main frequency via I2C, the two pull-up resistors do not need to be soldered.

 
After the firmware is burned, you can use a terminal tool such as PuTTY to open the chip's serial port to set the voltage and timing.
 
The attached file contains the firmware program.