Brief Functional Description

The easy to use hysteretic step-down converter provides high efficiency over a wide load and input range with few external components.

An advanced PFM control scheme gives this device the benefits of a PWM converter with high efficiency at heavy loads, while using very low operating current at light loads to maintain an excellent behaviour over load variation.

Maximum switching frequency of 300kHz permits small external components and operation to 100 duty cycle allows the lowest possible dropout voltage. For optimal flexibility an external shunt resistor sets the maximum output current.

特性 Features

? More than 90 efficiency and 100 duty cycle

? Wide input voltage range from 5V to 40V

? Integrated 1.6A on-chip P-channel MOS power switch

? 12μA typical shutdown current

? Less than 0.5V drop voltage at 500mA output current

? 0.2V to Vinput adjustable output range

? Controllable VOUT via an external Reference

? No control loop compensation required

? Improved current-limited PFM converter

? Maximum operating frequency > 300kHz

? Power good, reset or watchdog signal

? Under-voltage lockout and thermal shutdown

? -40°C to 125°C junction temperature

? Available in thermally enhanced TSSOP24 package

Applications

? Automotive electronics

? Minimum component step-down converter

? Sequenceable POL power supply systems

? Externally controllable LED power supply

? Externally controllable power amplifier