Description

The APW7057 is a 300kHz constant frequency voltage mode synchronous switching controller that drives external N-channel MOSFETs. The upper MOSFET remains on when the input supply drops close to the output, achieving a 100% duty cycle. The internal loop compensation is optimized for fast transient response, eliminating the need for an external compensation network. This model features a precision 0.8V reference, making it suitable for a wide variety of low voltage applications. The soft-start time is internally set to 2ms, limiting the input in-rush current and preventing output overshoot during powering up.

Specifications and Features

• Operates from +5V Input
• 0.8V Internal Reference Voltage
• ±1.5% Accuracy Over Line, Load and Temperature
• 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
• Lead Free and Green Devices Available (RoHS Compliant)

Application Scenarios

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