Integrated laptop chip Richtek RT8243AZQW. The RT8243A/B/C is a dual voltage regulator, switch-mode power supply (SMPS) controller that provides logic supplies for battery-powered systems. It includes two PWM controllers adjustable from 2V to 5.5V and two fixed 5V/3.3V regulators. One of the controllers (LDO5) provides automatic switchover to the BYP1 input, which is connected to the main SMPS1 output for maximum efficiency. An optional external charge pump can be monitored via SECFB (RT8243B/C). Other features include programmable current output, power-good output, internal soft-start, and soft discharge output that prevents negative voltage during shutdown.