LM2751 Datasheet | National Semiconductor

Description The LM2751 is a constant frequency switched capacitor charge pump with regulated output voltage options of 4.5V, and 5.0V. Over the input voltage range of 2.8V to 5.5V the LM2751 provides up to 150m A of output current and requires only four low-cost ceramic capacitors. The LM2751 provides excellent efficiency without the use of an inductor by operating the charge pump in a gain of 3/2 or 2. The proper gain for maintaining regulation is chosen so that efficiency is maximized over the input voltage range. LM2751 uses constant frequency pre-regulation to minimize conducted noise on the input and provide a predictable switching frequency. The switching frequency is programmable to 725k Hz, 300k Hz, 37k Hz, or 9.5k Hz. LM2751 is available in a 10-pin Leadless Leadframe No Pullback Package: LLP-10. Features Regulated Output Options: 4.5V, 5.0V Output Voltage Regulated within 3% Peak Efficiency Over 90% 150m A (4.5V) or 80m A (5.0V) Output Current Capability Input Voltage Range: 2.8V to 5.5V Low Input and Output Voltage Ripple < 1µA Typical Shutdown Current Small Solution Size - NO INDUCTOR Programmable 725k Hz, 300k Hz, 37k Hz, or 9.5k Hz Switching Frequencies n 10-pin LLP No-Pullback Package: 3mm x 3mm x 0.8mm n n n n n n n n n Applications n White LED Display Backlights n White LED Keypad Backlights n General Purpose 2x, 1.5x Regulated Charge Pump Typical Application Circuit LM2751 2x/1.5x Efficiency vs. 2x Charge Pump Effciency © 2005 National Semiconductor Corporation DS201121 .national. Connection Diagram 10-pin Leadless Leadframe Package (LLP-10) No Pullback 3mm x 3mm x 0.8mm NS Package Number SDA10A .. Pin Descriptions Pin # 1 2 3 4 5 6 7 8 9 10 Name VOUT C1+ VIN CS0 CS1 EN C2- GND C1- C2+ Pre-Regulated Output. Flying Capacitor C1 Connection. Input Supply Range: 2.8V to 5.5V. Frequency Select Input 0. Frequency Select Input 1. Enable Pin Logic Input. Flying Capacitor C2 Connection. Ground. Flying Capacitor C1...