基于MIC2166设计的自适应降压电源控制技术

本文介绍了MIC2166主要特性，方框图，应用电路以及8V-24V 到1.2V/10A评估板电路图和评估板材料清单（BOM）。

MIC2166是Micrel公司的同步自适应降压电源控制器，工作电压4.5V到28V，工作频率600kHz，输出电流高达25A，输出电压可调低至0.8V，精度±1%。主要用于STB，网关，路由器和DSL调制解调器，打印机，扫描仪，图像和视频卡，服务器，PC和处理器核电源以及低压分布电源。The Micrel MIC2166 is a synchronous adaptive on-time buck controller targeting high performance, cost sensitive applications such as set-top boxes, gateways, routers, computing peripherals, and telecom/networking equipment.

The MIC2166 operates over a supply range of 4.5V to 28V. It has an internal linear regulator which provides a regulated 5V supply to power the internal control circuitry.

MIC2166 operates at a constant 600kHz switching frequency and can be used to drive up to 25A of output current. The output voltage is adjustable down to 0.8V.

A unique Hyper Speed Control™ architecture enables ultra-fast transient response while reducing the output capacitance and also makes High VIN/Low VOUT operation possible.A UVLO feature is provided to ensure proper operation under power-sag conditions to prevent the external power MOSFET from over heating. Also, a soft-start feature is provided to reduce the inrush current. Short current sensing on the bottom MOSFET with hiccup mode operation ensures protection in case of an output short circuit. Further, the MIC2166 includes an EN pin to shut down the converter and a PGOOD pin to allow simple sequencing.

The MIC2166 is available in a 10 pin MSOP ePad package with a junction operating termperature range from –40℃ to +125℃. All support documentation can be found on
Micrel’s web site at: www.micrel.com.

MIC2166主要特性：

• Hyper Speed Control™ architecture enables

- High delta V operation (VIN=28V and VOUT=0.8V)

- Smallest output capacitance

• Built-in 5V regulator for single-supply operation

• Any CapacitorTM stable

- Zero ESR to high ESR

• Power-Good output

• Input voltage range: 4.5V to 28V

• 5μA typical shutdown current

• 25A output current drive capability

• Output down to +0.8V with ±1% accuracy

• 600kHz switching frequency

• Internal 5ms digital soft-start

• Thermal shutdown and hiccup current limit protection

• No external current-sense resistor required

• Pre-bias output safe

• 10-pin MSOP ePad package

• –40℃ to +125℃ junction temperature range

MIC2166应用：

• Set-top box, gateways, routers and DSL modems

• Printers, scanners, graphic and video cards

• Servers, PCs and processor core supply

• Low-Voltage Distributed Power

图1。MIC2166方框图

图2。MIC2166可调输出600kHz降压转换器

图3。MIC2166 8V-24V 到1.2V/10A评估板电路图

评估板材料清单（BOM）：