LM1770 Datasheet | Texas Instruments

FEATURES - 2 Input Voltage Range of 2.8V to 5.5V - 0.8V Reference Voltage - No pensation Required - Constant Frequency Across Input Range - Low Quiescent Current of 400µA - Internal Soft-start - Short Circuit Protection - 5-Pin SOT-23 Package APPLICATIONS - Simple To Design, High Efficiency Step Down Switching Regulators - Set-Top Boxes - Cable Modems - Printers - Digital Video Recorders - Servers DESCRIPTION The LM1770 is an efficient synchronous buck switching controller in a tiny SOT-23 package. The constant on-time control scheme provides a simple design free of pensation ponents, allowing minimal ponent count and board space. It also incorporates a unique input feed-forward to maintain a constant frequency independent of the input voltage. The LM1770 is optimized for a low voltage input range of 2.8V to 5.5V and can provide an adjustable output as low as 0.8V. Driving an external high side PFET and low side NFET it can provide efficiencies as high as 95%. Three versions of the LM1770 are available depending on the switching frequency desired for the application. Nominal switching frequencies are in the range of 100k Hz to 1000k Hz. Typical Application Circuit VOUT FB GND 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 date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2005- 2013, Texas Instruments Incorporated SNVS403C - SEPTEMBER 2005 - REVISED APRIL 2013 Connection Diagram VIN 1 GND 2 LG 3 5 FB 4 HG Figure 1. 5-Pin SOT-23 (Top View) See DBV Package .ti. Pin Functions Pin # 1 2 3 4...