LM1771 Datasheet | Texas Instruments

Features - 1 Input Voltage Range of 2.8 V to 5.5 V - 0.8-V Reference Voltage - Precision Enable - No pensation Required - Constant Frequency Across Input Range - Low Quiescent Current of 400 µA - Internal Soft-Start - Short Circuit Protection - 6-Pin WSON Package and 8-Pin VSSOP Package 2 Applications - Simple-to-Design, High-Efficiency, Step-Down Switching Regulators - FPGAs, DSPs, and ASIC Power Supplies - Set-Top Boxes - Cable Modems - Printers - Digital Video Recorders - Servers - Graphic Cards 3 Description The LM1771 device is an efficient synchronous buck switching controller with a precision enable requiring no external pensation. The constant ON-time control scheme provides a simple design free of pensation ponents, allowing minimal ponent count and board space. The precision enable pin allows flexibility in sequencing multiple rails and setting UVLO. The LM1771 also incorporates a unique input feedforward to maintain a constant frequency independent of the input voltage. The LM1771 is optimized for a low-voltage input range of 2.8 V to 5.5 V and can provide an adjustable output as low as 0.8 V. Driving an external high-side PFET and low-side NFET, it can provide efficiencies as high as 95%. Three versions of the LM1771 are available depending on the switching frequency desired for the application. Nominal switching frequencies are in the range of 100 k Hz to 1000 k Hz. Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) WSON (6) VSSOP (8) 3.00 mm × 3.00 mm 3.00 mm × 3.00 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Typical Application Circuit EN EN VOUT An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. SNVS446D - JUNE 2006 - REVISED JANUARY...