The SM8158C is a power management IC with charge pump type white LED driver and 2-system programmable LDO (Low Dropout Regulator). The white LED driver provides constant-current drive for 1 to7 backlight LEDs connected in parallel. The 7 channel LED driver pins can be grouped into 2 systems (7:0,6:1,5:2,4:3) to provide 2-system variable brightness lighting. The GPO (General Purpose Output) is a 20mA constant-current LED drive that can also be used as an open-drain output pin. The charge pump automatically switches between ×1 mode, ×1.5 boost mode, and ×2 boost mode in response to battery voltage, LED drive current, and VF_LED (LED forward bias voltage drop) conditions in order to extend battery drive life. An ALC (Automatic Luminance Control) function is built-in that automatically adjusts the dimming in response to the ambient light. Conventional dimming control that does not employ the ALC can also be selected. The operating mode settings are accessed using an I²C^*1 interface, allowing LED drive current, LDO voltage, output ON/OFF, and other settings to be controlled from a microcontroller.
*1: I²C-BUS is a registered trademark of NXP B.V.