LM2792 Datasheet | National Semiconductor

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 34m A of load current to acmodate two high forward voltage (typically white) LEDs. The switching frequency is 900k Hz (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 34m A output current Soft start limits inrush current Analog brightness control Separate shutdown input Very small solution size and no inductor 1.4m A typical operating current 1µA (max.) shutdown current 900k Hz switching frequency (min.) Linear regulation generates predictable noise spectrum LLP-10 package: 3mm X 3mm X 0.8mm Applications n White LED Display Backlights n White LED Keypad Backlights n 1-Cell Li-Ion battery-operated equipment including PDAs, hand-held PCs, cellular phones n Flat Panel Dispalys Basic Application Circuit © 2002 National Semiconductor Corporation DS200242 .national. Connection Diagram Top View 10-Lead LLP Ordering Information Order Number LM2792LD-L LM2792LDX-L LM2792LD-H LM2792LDX-H Shutdown Polarity Active Low Active Low Active High Active High NSC Package Drawing LLP-10 LLP-10 LLP-10 LLP-10 Package Marking SRB SRB...