FAN8303 is a 2A, 370kHz single-chip integrated buck regulator with an integrated power transistor (MOSFET). It is simple to use and requires only minimal external components. This technical application note will explain how to use FAN8303 to generate negative voltage. The document will introduce application examples and discuss the best design for boost-buck circuits.
This document is an application note (AN-8023) from Fairchild Semiconductor regarding the FAN8303, a 2A synchronous buck regulator. It details how to utilize this component to generate negative output voltages, a common requirement for LCD panel column drivers and other applications. The text explains that while charge pumps are simple, they suffer from power loss and poor regulation; the FAN8303 offers a solution for generating negative outputs with better performance.
The guide covers the operating principles of buck-boost topologies, specifically comparing standard buck converters to buck-boost configurations. It provides specific design equations and considerations for selecting the inductor, output and input capacitors, and the freewheeling diode. A detailed design example is provided, calculating component values for a 12V input to -5V output at 1A with a 370kHz switching frequency. The document concludes with general waveform descriptions and efficiency/power loss charts. This manual is written in Chinese.
| Integrated MOSFET | 2A |
|---|---|
| Switching Frequency | 370kHz |
| Input Voltage Range | -23V to 23V |
| Switching Frequency (Fixed) | 370 kHz |
It overcomes the power loss and poor output voltage adjustment found in charge pump designs.
A Schottky diode is recommended due to its low forward voltage drop.
The switching frequency is fixed at 370 kHz.