TPS61043

Features:

` Current Source with 18 V Overvoltage Protec- tion
` Powers Up to 4 LEDs in Series
` Input Voltage Range . . 1.8 V to 6.0 V
` Internal 30 V Switch
` Up to 85% Efficiency
` Precise Brightness Control Using PWM Signal or Analog Signal
` Switching Frequency . . Up to 1 MHz
` Internal Power MOSFET Switch . . 400 mA
` Operates With Small Output Capacitors Down to 100 nF
` Disconnects LEDs During Shutdown
` No Load Quiescent Current . . 38 A Typ
` Shutdown Current . . 0.1 A Typ
` Available in a Small 3 mm ´ 3 mm QFN Package

Application

` White LED Supply for Display Backlight/Sidelight in
    PDA, Pocket PC, Smart Phones
    Handheld Devices
    Cellular Phones


Pinout




Specifications

	TPS61043
Supply voltage VIN (2)	-0.3 V to 7 V
Voltages, V(Rs), V(CTRL) , V(FB)	-0.3 V to Vin + 0.3 V
Voltages, V(SW), V(LED) (2)	30 V
Voltage, V(OVP)	30 V
Continuous power dissipation	See Dissipation Rating Table
Operating junction temperature range	-40°C to 150°C
Storage temperature range, TSTG	-65°C to 150°C
Lead temperature (soldering, 10 sec)	260°C

Description

The TPS61043 is a high frequency boost converterwith constant current output that drives white LEDs or similar.The LED current is set with the external sense resistor (RS) and is directly regulated by the feedback pin (FB) that regulates the voltage across the sense resistor RS to 252 mV (typ). To control LED brightness, the LED current can be pulsed by apply- ing a PWM (pulse width modulated) signal with a frequency range of 100 Hz to 50 kHz to the control pin (CTRL). To allow higher flexibility, the TPS61043 can be configured where the brightness can be controlled abypplaicnataionnaloingfosrmigantaiol nassewcetilol ,n.asTodeasvcoriibdedpoinssitbhlee leakage currents through the LEDs during shutdown the control pin (CTRL) disables the device and disconnects the LEDs from ground. For maximum safety during operation, the output has integrated overvoltage protection that prevents damage to the TPS61043 by limiting the output voltage to typically 18 V in case of a high impedance output (e.g. faulty LED).The TPS61042 device provides a solution for applications where higher LED currents or more than four LEDs in series need to be powered.