LM2758 Datasheet | National Semiconductor

.Data Sheet.in LM2758 Switched Capacitor Flash LED Driver in micro SMD October 9, 2009 LM2758 Switched Capacitor Flash LED Driver in micro SMD General Description LM2758 is an integrated low-noise, high-current switched capacitor DC/DC converter with a regulated current sink. The device is capable of driving loads up to 700 m A from a singlecell Li-Ion battery. Maximum efficiency is achieved over the input voltage range by actively selecting the proper gain based on the LED forward voltage and current requirements. One external low-power resistor sets the desired current for Indicator, Torch and Flash modes. To protect the devices and the flash LED, internal Time-out circuitry turns off the LM2758 in case of a faulty prolonged Flash mode. Internal soft-start circuitry limits the amount of inrush current during start-up. LM2758 is offered in National’s tiny 12-bump thin micro SMD package. Features - Up to 700 m A Output Current - Ultra-Small Solution Size - No Inductor, Only 4 Capacitors and a resistor Required - 1.514 mm x 1.996 mm x 0.6 mm thin micro SMD package 90% Peak Efficiency Indicator, Torch and Flash Modes Time-Out Circuitry Limits Flash Duration to 814 msec. (typ.) Adaptive 1x and 1.5x Gains for Maximum Efficiency True Shutdown Internal Soft-Start Eliminates Inrush Current - - - - - - Applications - Camera Flash in Mobile Phones - Flash for Digital Cameras Typical Application Circuit © 2009 National Semiconductor Corporation .national. .Data Sheet.in Connection Diagram 12-Bump Thin Micro SMD 1.514mm x 1.996mm x 0.6mm NS Package Number TLA12 Pin Descriptions Pin C1 B2 B1 D2 C2 D1 A2 C3 A1 B3 A3 D3 Name VIN CPOUT C1+ C1- C2+ C2- SGND LED- EN1 EN2 ISET PGND Analog and control ground for charge pump. This pin should be connected directly to a low impedance ground plane. Regulated current source output. Connect flash LED cathode to this pin. The EN1 and EN2 pins are used to select the modes (Torch,...