SLUSDC7A March 2020 – November 2020 BQ25306
In some application cases, the charge current needs to be controlled by a MCU. In those cases, the GPIOs of the MCU can be used for on/off control of the charge current setting resistors RICHG1 and RICHG2 as shown in Figure 10-9. With GPIO1 and GPIO2 on/off control, three levels of charge current can be programmed. If the charge current needs to be controlled smoothly in a wide range, a PWM output of the MCU can be used to generate an average DC voltage output to program the charge current as show in Figure 10-10. The charge current can be calculated as: (1V - VPWM) / (RICHG1 + RICHG2). VPWM is the averaged DC voltage of the PWM output and it must be lower than 1 V. The regulated voltage at the ICHG pin is 1 V.