LM3691

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3691 SNVS506J – MAY 2008 – REVISED DECEMBER 2015 LM3691 High-Accuracy, Miniature 1-A Step-Down DC-DC Converter for Portable Applications 1 Features 1 Input Voltage: 2.3 V to 5.5 V Output Voltage: 0.75 V to 3.3 V ±1% DC Output Voltage Precision 4-MHz Switching Frequency 64-μA (typical) Quiescent Current in ECO Mode 1-A Maximum Load Capability Automatic ECO/PWM Mode Switching MODE Pin to Select ECO/Forced PWM Mode Current Overload and Thermal Shutdown Protections Only Three Tiny Surface-Mount External Components Required (Solution Size Less Than 15 mm2) 2 Applications Mobile Phones Hand-Held Radios MP3 Players Portable Hard Disk Drives Typical Application Circuit VIN 2.3 V to 5.5 V CIN IN A2 B2 SW EN A1 LM3691 C1 FB VOUT COUT GND C2 B1 MODE 3 Description The LM3691 step-down DC-DC converter is optimized for powering ultra-low-voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 1-A load current over an input voltage range from 2.3 V to 5.5 V. There are several different fixed voltage output options available. The LM3691 has a mode-control pin that allows the user to select Forced PWM mode or ECO mode that changes modes between gated PWM mode and PWM automatically, depending on the load. In ECO mode, the device offers superior efficiency and very low IQ under light load conditions. ECO mode extends the battery lif...