General Description

The XL1509 is a 150 KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 2A load with high efficiency, low ripple and excellent line and load regulation. Requiring a minimum number of external components, the regulator is simple to use and include internal frequency compensation and a fixed-frequency oscillator. The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An enable function, an over current protection function is built inside. When second current limit function happens, the operation frequency will be reduced from 150KHz to 50KHz. An internal compensation block is built in to minimize external component count.

Datasheet

Features

• Wide 4.5V to 40V Input Voltage Range
• 3.3V,5V,12V, and adjustable versions
• Output Adjustable from 1.23V to 37V
• Maximum Duty Cycle 100%
• Minimum Drop Out 1.5V
• Fixed 150KHz Switching Frequency
• 2A Constant Output Current Capability
• Internal Optimize Power Transistor
• High efficiency
• Excellent line and load regulation
• TTL shutdown capability
• ON/OFF pin with hysteresis function
• Built in thermal shutdown function
• Built in current limit function
• Built in second current limit function
• Available in SOP8L package

Applications

• LCD Monitor and LCD TV
• Digital Photo Frame
• Set-up Box
• ADSL Modem
• Telecom / Networking Equipment