LM2798

OBSOLETE LM2797, LM2798 www.ti.com SNVS199C – MAY 2004 – REVISED SEPTEMBER 2011 LM2797/LM2798 120mA High Efficiency Step-Down Switched Capacitor Voltage Converter with Voltage Monitoring Check for Samples: LM2797, LM2798 FEATURES 1 2 Output Voltage Options: – 2.0V ± 5%, 1.8V ± 5%, and 1.5V ± 6% 120mA Output Current Capability Multi-Gain and Gain Hopping for Highest Possible Efficiency - up to 90% Efficient 2.6V to 5.5V Input Range Input and Output Voltage Monitoring (BATOK and POK) Low Operating Supply Current: 35µA Shutdown Supply Current: 0.1µA Thermal and Short Circuit Protection LM2798 Turn-on Time: 400µs – LM2797 Turn-on Time: 100µs Available in an 10-Pin VSSOP Package APPLICATIONS Cellular Phones Pagers H/PC and P/PC Devices Portable Electronic Equipment Handheld Instrumentation DESCRIPTION The LM2797/98 switched capacitor step-down DC/DC converters efficiently produce a 120mA regulated lowvoltage rail from a 2.6V to 5.5V input. Fixed output voltage options of 1.5V, 1.8V, and 2.0V are available. The LM2797/98 uses multiple fractional gain configurations to maximize conversion efficiency over the entire input voltage and output current ranges. Also contributing to high overall efficiency is the extremely low supply current of the LM2797/98: 35µA operating unloaded and 0.1µA in shutdown. Features of the LM2797/98 include input voltage and output voltage monitoring. Pin BATOK provides battery monitoring by indicating when the input voltag...