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MIC2169B
(Rev.:2009)

500kHz PWM Synchronous Buck Control IC

Micrel 

MIC2169B

500kHz PWM Synchronous Buck

Control IC

General Description

Features

The MIC2169B is a high-efficiency, simple to use 500kHz

PWM synchronous buck control IC housed in a small

MSOP-10 ePad package. It allows compact DC/DC

solutions with a minimal external component count and

cost. The device features high output driver capability to

drive loads up to 30A.

• 3V to 14.5V input voltage range

• Adjustable output voltage down to 0.8V

• 500kHz PWM operation

• Up to 95% efficiency

• Output Pre-biased Protection

The MIC2169B operates from a 3V to 14.5V input, without

the need of any additional bias voltage. The output voltage

can be precisely regulated down to 0.8V. The adaptive all

N-Channel MOSFET drive scheme allows efficiencies over

95% across a wide load range within the smallest possible

printed circuit board space area.

The MIC2169B senses current across the high-side N-

Channel MOSFET, eliminating the need for an expensive

and lossy current-sense resistor. Current limit accuracy is

maintained by a positive temperature coefficient that tracks

the increasing RDS(ON) of the external MOSFET. Further

cost and space are saved by the internal in-rush-current

limiting digital soft-start. The MIC2169B is identical to the

MIC2169A except it supports pre-bias loads. Internal pre-

bias circuit prevents output voltage drooping and

excessive reverse inductor current when powering up with

a pre-bias voltage at the output.

• Build-in 2.2Ω drivers to drive two N-channel MOSFETs

• Adaptive gate drive increases efficiency

• Simple voltage-mode PWM control with externally

compensated

• Short minimum ON time of 30ns allowing very low duty

cycle

• Fast transient response

• Adjustable current limit senses high-side N-Channel

MOSFET current

• Hiccup mode short-circuit protection

• No external current-sense resistor

• Internal soft-start current source

• Dual function COMP and EN pin allows low-power

shutdown

• Available in a small size 10-pin MSOP ePad package

The MIC2169B is available in a thermally capable 10-pin

ePad MSOP package, with a wide junction operating

range of -40°C to +125°C.

All support documentation can be found on Micrel’s web

site at www.micrel.com.

Applications

• Point-of-load DC/DC conversion

• High Current Power Supplies

• Telecom/Datacom and Networking Power Supplies

• Servers and Workstations

• Graphic cards and other PC Peripherals

• Set-top boxes

• LCD power supplies

___________________________________________________________________________________________________________

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

June 2009

M9999- 060309-A

(408) 944-0800

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