MIC2174/MIC2174C

Synchronous Buck Controller

Featuring Adaptive On-Time Control

40V Input, 300kHz

Hyper Speed Control™ Family

Hyper Speed Control and Any Capacitor are trademarks of Micrel, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

General Description

The Micrel MIC2174/MIC2174C is a fixed-frequency,

synchronous buck controller featuring adaptive on-time

control. The MIC2174/MIC2174C operates over an input

supply range of 3V to 40V at a fixed switching frequency of

300kHz and is capable of driving 25A of output current.

The output voltage is adjustable down to 0.8V.

A unique Hyper Speed Control™ architecture allows for

ultra-fast transient response while reducing the output

capacitance. It also makes ultra-fast transient response

while reducing the output capacitance and also allows for

extremely low duty-cycle operation. The MIC2174 /

architecture. A UVLO is provided to ensure proper

operation under power-sag conditions to prevent the

external power MOSFET from overheating. A soft-start is

provided to reduce inrush current. Foldback current limit

and “hiccup” mode short-circuit protection ensure FET and

load protection.

The MIC2174/MIC2174C is available in a 10-pin MSOP

(MAX1954A-compatible) package with an operating

junction temperature range from –40

°C to +125°C.

All support documentation can be found on Micrel’s web

site at: www.micrel.com.

Features

•

Hyper Speed Control™ architecture enables:

– Smaller output capacitors than competitors

•

3V to 40V input voltage

•

Any Capacitor

-

Zero ESR to high ESR

•

300kHz switching frequency

•

•

•

±1% FB accuracy (MIC2174)

•

±3% FB accuracy (MIC2174C)

•

Up to 94% efficiency

•

Foldback current limit and “hiccup” mode short-circuit

protection

•

Thermal shutdown

•

Safe start-up into pre-biased loads

•

–40

°C to +125°C junction temperature range

Applications

•

Telecom Networking

•

Industrial Equipment

•

Distributed DC power systems

____________________________________________________________________________________________________________

Typical Application

Synchronous Buck Controller Featuring Adaptive On-Time Control

12V to 3.3V Efficiency

50

55

60

65

70

75

80

85

90

95

100

02

46

8

OUTPUT CURRENT (A)

10

VIN=5V

September 2010

M9999-091310-C