MIC26901

28V, 9A Hyper Speed Control

™

Synchronous DC/DC Buck Regulator

SuperSwitcher II

™

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

MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.

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

General Description

The Micrel MIC26901 is a constant-frequency, synchronous

buck regulator featuring a unique adaptive on-time control

architecture. The MIC26901 operates over an input supply

range of 4.5V to 28V and provides a regulated output of up to

9A of output current. The output voltage is adjustable down to

0.8V with a guaranteed accuracy of ±1%, and the device

operates at a switching frequency of 600kHz.

Micrel’s Hyper Speed Control

™ architecture allows for ultra-

fast transient response while reducing the output capacitance

advantages of fixed-frequency operation and fast transient

response in a single device.

The MIC26901 offers a full suite of protection features to

ensure protection of the IC during fault conditions. These

include undervoltage lockout to ensure proper operation

under power-sag conditions, internal soft-start to reduce

inrush current, foldback current limit, “hiccup mode” short-

circuit protection and thermal shutdown. An open-drain

Power Good (PG) pin is provided.

All support documentation can be found on Micrel’s web

site at: www.micrel.com.

Features

•

Hyper Speed Control

™ architecture enables

-

-

Small output capacitance

•

4.5V to 28V voltage input

•

9A output current capability, up to 95% efficiency

•

Adjustable output from 0.8V to 5.5V

•

±1% feedback accuracy

•

Any Capacitor

™ stable -zero-to-high ESR

•

600kHz switching frequency

•

No external compensation

•

Power Good (PG) output

•

Foldback current-limit and “hiccup mode” short-circuit

protection

•

Supports safe startup into a pre-biased load

•

–40

°C to +125°C junction temperature range

•

28-pin 5mm

Applications

•

Distributed power systems

•

Communications/networking infrastructure

•

Set-top box, gateways and routers

•

Printers, scanners, graphic cards and video cards

___________________________________________________________________________________________________________

Typical Application

vs. Output Current

50

55

60

65

70

75

80

85

90

95

100

02

46

8

10

1

OUTPUT CURRENT (A)

2

5.0V

3.3V

2.5V

1.8V

1.5V

1.2V

1.0V

0.9V

0.8V

July 2011

M9999-071311-A