EUP2794 Datasheet | Eutech Microelectronics

DESCRIPTION The EUP2794 is a low noise, constant frequency charge pump that uses a dual mode load switch (1X) and fractional (1.5X) conversion to maximize efficiency for white LED applications. The EUP2794 delivers up to 80m A of load current and provides four regulated current sources, each capable of driving up to 20m A through white LEDs. All LED pin currents are regulated, constant and tightly matched to achieve uniformity of brightness across the LCD backlight. The switching frequency is 900k Hz.(typ.) to keep the .. conducted noise spectrum away from sensitive frequencies within portable RF devices. An external resistor (RSET) sets the current in each of the LED outputs. In addition, brightness can be controlled by both linear and PWM techniques. An analog voltage between 0V and 3.0V may be applied to the BRGT pin to linearly vary the LED current. By adjusting current with BRGT pin , the brightness of the LEDs can be smoothly varied. Alternatively, a PWM digital signal can be applied to the SD pin to vary the perceived brightness of the LED. The EUP2794 is available in a 16-pin 3mm × 3mm QFN package. FEATURES z z z z z z z z z z z Regulated Current Sources with 0.6% Mis-matching between any Two Outputs High Efficiency 1.5X Charge Pump Drives One, Two, Three or Four White LEDs 2.7V to 5.5V Input Voltage Up to 80m A Output Current Analog or PWM Brightness Control Soft Start Function Low Shutdown Current 900k Hz Switching Frequency (typ.) Tiny 3mm × 3mm QFN-16 Package Ro HS pliant and 100% Lead(Pb)-Free APPLICATIONS z z White LED Backlighting 1-Cell Li-Ion battery-operated equipment including PDAs, hand-held PCs, cellular phones Typical Application Circuit Figure 1. DS2794 Ver0.5 Mar. 2006 Typical Application Circuit .. Figure 2. Pin Configurations Part Number Pin Configurations EUP2794 QFN-16 Pin Description PIN C2P POUT SD BRGT ISET LED1-4 GND C1N VIN C2N C1P Pin 1 2 3 5 6 8,7,10,9 11 13 14 15 16 DESCRIPTION Positive terminal of C2 Charge pump...