Sync-Rect PFM Step-Up DC-DC Converter with Low-Battery Detector and Ring-Killer

NCP1411 is a monolithic micropower high frequency Boost (step−up) voltage switching converter IC specially designed for battery operated hand−held electronic products up to 250 mA loading. It integrates Synchronous Rectifier for improving efficiency as well as eliminating the external Schottky Diode. High switching frequency (up to 600 kHz) allows low profile inductor and output capacitor being used. Low−Battery Detector, Logic−Controlled Shutdown and Cycle−by−Cycle Current Limit provide value−added features for various battery−operated applications.

FEATUREs
• Pb−Free Package is Available
• High Efficiency, up to 92%
• Very Low Device Quiescent Supply Current of 9.0 A Typical
• Built−in Synchronous Rectifier (P−FET) Eliminates One External Schottky Diode
• High Switching Frequency (up to 600 kHz) Allows use of Small Size Inductor
• High Accuracy Reference Output, 1.19 V ± 0.6% @ 25°C, can supply more than 2.5 mA when VOUT ≥ 3.3 V
• Ring−Killer for Quiet Operation in Discontinuous Conduction Mode
• 1.0 V Startup at No Load Guaranteed
• Output Voltage from 1.5 V to 5.5 V Adjustable
• Output Current up to 250 mA @ VIN = 2.5 V, VOUT = 3.3 V
• Logic−Controlled Shutdown
• Open Drain Low−Battery Detector Output
• 1.0 A Cycle by Cycle Current Limit
• Low Profile and Minimum External Parts
• Compact Micro8 Package

Typical Applications
• Personal Digital Assistant (PDA)
• Handheld Digital Audio Product
• Camcorder and Digital Still Camera
• Handheld Instrument
• Conversion from One or Two NiMH or NiCd, or One Li−ion Cell to 3.3 V/5.0 V