The LM3520 is a dual step-up DC/DC converter, designed to drive up to 5 white LEDs with a constant current and to power an organic LED display with a constant voltage. A single external resistor is used to set the maximum LED current. The LED current can be adjusted by applying a PWM signal to the EN pin. For higher efficiency the LM3520 operates with pulse frequency modulation (PFM) control scheme when the sub-display is enabled. When Main display is enabled, the device is operating in PWM mode.
Overvoltage protection circuitry and a 1MHz switching frequency allow for the use of small, low cost external components.
Integrated OLED and white-LED driver
Drives up to 5 LEDs at 20mA/3.6V and 4 LEDs at 30mA/3.6V for main-display
Up to 20V@50mA/3.6V for sub-display
True shutdown isolation
Small External Components
1 MHz Switching Frequency
23V OverVoltage Protection
Wide Input Voltage Range: 2.7V to 5.5V
Cycle-By-Cycle Current Limit
PWM Dimming Control
Low Profile 14-Pin LLP(3mm x 4mm x 0.8mm)