LM3485MMX Datasheet PDF - TI

●Description

●The LM3485 is a high-efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, low-cost, switching buck regulator for a wide range of applications. The hysteretic control architecture provides for simple design without any control-loop stability concerns using a wide variety of external components. The PFET architecture also allows for low component count as well as ultralow dropout, 100% duty cycle operation. Another benefit is high efficiency operation at light loads without an increase in output ripple.

●Current limit protection is provided by measuring the voltage across the RDS(ON) of the PFET, thus eliminating the need for a sense resistor. The cycle-by-cycle current limit can be adjusted with a single resistor, ensuring safe operation over a range of output currents.

●Features

●• Easy-to-Use Control Methodology

●• No Control-Loop Compensation Required

●• 4.5-V to 35-V Wide Input Range

●• 1.242-V to VIN Adjustable Output Range

●• High Efficiency 93%

●• ±1.3% (±2% Over Temp) Internal Reference

●• 100% Duty Cycle

●• Maximum Operating Frequency > 1 MHz

●• Current Limit Protection

●Applications

●• Set-Top Box

●• DSL or Cable Modem

●• PC/IA

●• Auto PC

●• TFT Monitor

●• Battery-Powered Portable Applications

●• Distributed Power Systems

●• Always On Power