General Description
The APW7057 is a 300kHz constant frequency voltage mode synchronous switching controller that drives external N-channel MOSFETs. When the input supply drops close to output, the upper MOSFET remains on, achieving 100% duty cycle. Internal loop compensation is optimized for fast transient response, eliminating external compensation network. The precision 0.8V reference makes this part suitable for a wide variety of low voltage applications. Soft start is internally set to 2ms, limiting the input in-rush current and preventing the output from overshoot during powering up.

Features
• Operates from +5V Input
• 0.8V Internal Reference Voltage
    - ±1.5% Accuracy Over Line, Load and Temp.
• 0.8V to VCC Output Range
• Full Duty Cycle Range
    - 0% to 100%
• Internal Loop Compensation
• Internal Soft Start
    - Typical 2ms
• Programmable Over-Current Protection
    - Lossless Sensing Using MOSFET RDS (ON)
• Under-Voltage Protection
• Drives External N-Channel MOSFETs
• Shutdown Control
• Small SOP-8 Package

Applications
• Motherboard
• Graphics Cards
• Cable or DSL Modems, Set Top Boxes
• DSP Supplies
• Memory Supplies
• 5V Input DC-DC Regulators
• Distributed Power Supplies