The LM3697 11-bit LED driver provides high-performance backlight dimming for 1, 2, or 3 series LED strings while delivering up to 90% efficiency. The boost converter with integrated 1-A, 40-V MOSFET automatically adjusts to LED forward voltage to minimize headroom voltage and effectively improve LED efficiency. The LM3697 is a high-efficiency three-string power source for backlight or keypad LEDs in smart-phone handsets. The high-voltage inductive boost converter provides the power for three-series LED strings for display backlight and keypad functions (HVLED1, HVLED2, and HVLED3). An additional feature is a pulse width modulation (PWM) control input for content adjustable backlight control, which can be used to control any high-voltage current sink. The LM3697 is fully configurable via an I2C-compatible interface. The device operates over a 2.7-V to 5.5-V input voltage range and a −40°C to +85°C temperature range.