LM2794

LM2794, LM2795 www.ti.com SNVS168L – JANUARY 2002 – REVISED MAY 2013 LM2794 /LM2795 Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control Check for Samples: LM2794, LM2795 FEATURES 1 2 Regulated Current Sources with ±0.5% Matching between any Two Outputs High Efficiency 3/2 Boost Function Drives One, Two, Three or four White LEDs 2.7V to 5.5V Input Voltage Up to 80mA Output Current Analog Brightness Control Active-Low or High Shutdown Input ('94/95) Very Small Solution Size and no Inductor 2.3µA (typ.) Shutdown Current 325kHz Switching Frequency (min.) Constant Frequency Generates Predictable Noise Spectrum Thin DSBGA Package: 2.08mm X 2.403mm X 0.600mm High APPLICATIONS White LED Display Backlights White LED Keypad Backlights 1-Cell Li-Ion Battery-Operated Equipment Including PDAs, Hand-Held PCs, Cellular Phones DESCRIPTION The LM2794/95 is a fractional CMOS charge-pump that provides four regulated current sources. It accepts an input voltage range from 2.7V to 5.5V and maintains a constant current determined by an external sense resistor. The LM2794/5 delivers up to 80mA of load current to accommodate four White LEDs. The switching frequency is 325kHz. (min.) to keep the conducted noise spectrum away from sensitive frequencies within portable RF devices. Basic Application Circuit CIN 1PF C1 C2 VIN POUT C1+ 1PF C1C2+ 1PF LM2794/95 C2SD D1 D2 D3 D4 BRGT GND ISET CHOLD 1PF LED1 LED2 LED3 LED4 RSET 1 P...