LM2792

LM2792 Current Regulated Switched Capacitor LED Driver with Analog Brightness Control July 2002 LM2792 Current Regulated Switched Capacitor LED Driver with Analog Brightness Control General Description The LM2792 is a CMOS charge-pump voltage doubler and regulator that provides two regulated current sources. They are designed to drive two white (or blue) LEDs with matched currents (within ± 0.3%) to produce balanced light sources for display backlights. The LM2792 accepts an input voltage range from 3.0V to 5.8V and maintain a constant current determined by an external set resistor. The LM2792 delivers up to 34mA of load current to accommodate two high forward voltage (typically white) LEDs. The switching frequency is 900kHz (min.) to keep the conducted noise spectrum away from sensitive frequencies within portable RF devices. The LM2792 offers full off to maximum current control through the BRGT pin. The output current linearly tracks the BRGT pin voltage. The LM2792 is available in active high or low shutdown versions. The shutdown pin reduces the operating current to 1µA (max.). The LM2792 is available in a 10 pin leadless leadframe (LLP) CSP package. Features n n n n n n n n n n n n n Output matching of ± 0.3% (typ.) Drives up to two LED’s 3.0V to 5.8V Input Voltage Up to 34mA output current Soft start limits inrush current Analog brightness control Separate shutdown input Very small solution size and no inductor 1.4mA typical operating current 1µA (max.) shutdown curr...