LM2771 Datasheet | National Semiconductor

Description The LM2771 is a switched capacitor step-down regulator that produces a 1.5V output without the use of an inductor. It is capable of supplying loads up to 250m A. The LM2771 operates with an input voltage from 2.7V to 5.5V, and requires only 3 low-cost ceramic capacitors. The LM2771 uses a regulated 0.5x charge pump to give power conversion efficiencies nearly twice as high as an LDO. Pre-regulated 1.1MHz fixed-frequency switching results in very low ripple and noise on both the input and the output. When output currents are low ( < 30m A typ.), the part automatically switches to a low-ripple PFM regulation mode to maintain high efficiency over the entire load range. At input voltages below 3.5V (Typ), the charge pump goes into pass mode, with efficiencies similar to an LDO. The LM2771 is available in National’s 10-pad Leadless Leadframe No-Pullback Package (LLP-10). Features n n n n n n n n n n n n Low-Noise Fixed Frequency Operation 1.5V Output Voltage Li-Ion (3.6V) to 1.5V with 81% Efficiency 1.7% Output Voltage Accuracy Very Low Output Ripple: 8m V @ 250m A Output Currents up to 250m A 2.7V to 5.5V Input Range Shutdown Disconnects Load from VIN 1.1MHz Switching Frequency No Inductors…Small Solution Size Current Limit and Thermal Protection LLP-10 Package (3mm x 3mm x 0.8mm) Applications n DSP, Memory, and Microprocessor Power Supplies n Mobile Phones and Pagers n Portable Electronic Devices Typical Application Circuit LM2771 Efficiency vs. Low-Dropout Linear Regulator (LDO) Efficiency © 2006 National Semiconductor Corporation DS201838 .national. Connection Diagram and Package Mark Information 10-Pin Non-Pullback Leadless Frame Package (LLP-10) National Semiconductor Package Number SDA10A Pin Descriptions Pin # 1 2 3 4 5 6 7 8 9 10 Name VIN GND VOUT NC NC C1C1+ NC GND EN Ground Output Voltage No Connect No Connect Flying Capacitor 1: Negative Terminal Flying Capacitor 1: Positive Terminal No Connect Ground...