LM2771 Datasheet | Texas Instruments

FEATURES - 2 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 - WSON-10 Package (3mm × 3mm × 0.8mm) APPLICATIONS - DSP, Memory, and Microprocessor Power Supplies - Mobile Phones and Pagers - Portable Electronic Devices 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 fixedfrequency 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. Typical Application Circuit VIN = 3.0V to 5.5V CIN 1 PF VOUT VOUT: 1.5V IOUT up to 250 m A COUT 4.7PF GND EN C1+ Cfly 1 PF C1- Capacitors: 1 PF - TDK C1005X5R1A105K 4.7 PF - TDK C1608X5R0J475K or equivalent Figure 1. Figure 2. LM2771 Efficiency vs. Low-Dropout Linear Regulator (LDO) Efficiency Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication...