LM2773

LM2773 Low-Ripple 1.8V/1.6V Spread-Spectrum Switched Capacitor Step-Down Regulator January 22, 2008 LM2773 Low-Ripple 1.8V/1.6V Spread-Spectrum Switched Capacitor Step-Down Regulator General Description The LM2773 is a switched capacitor step-down regulator that produces a selectable 1.8V or 1.6V output. It is capable of supplying loads up to 300mA. The LM2773 operates with an input voltage from 2.5V to 5.5V, accommodating 1-cell Li-Ion batteries and chargers. The LM2773 utilizes a regulated charge pump with gains of 2/3x and 1x. It has very low ripple and noise on both the input and output due to its pre-regulated 1.15MHz (typ.) switching frequency and spread spectrum operation. When output currents are low, the LM2773 automatically switches to a lowripple PFM regulation mode to maintain high efficiency over the entire load range. The LM2773 is available in National’s 0.5mm pitch 9-bump Micro-SMD (µSMD-9). Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low-Noise Spread Spectrum Operation 1.8V/1.6V Selectable Output Voltage 2% Output Voltage Regulation > 75% Efficiency in 1.8V Mode Very Low Output Ripple: 10mV @ 300mA Output Currents up to 300mA 2.5V to 5.5V Input Voltage Range Shutdown Disconnects Load from VIN 1.15MHz Switching Frequency No Inductors…Small Solution Size Short Circuit and Thermal Protection 0.5mm pitch, µSMD-9 (1.511 × 1.511mm × 0.6mm) Applications ■ Power Supply for DSP's, Memory, and Microprocessors ■ Mobile Phones and Pagers ■ Digital Cameras, Portable Music Player...