MP2106 – 1.5A, 15V, 800KHz SYNCHRONOUS BUCK CONVERTER

MP2106 Rev. 1.6

www.MonolithicPower.com

3

2/22/2006

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© 2006 MPS. All Rights Reserved.

TM

Parameter

Symbol Condition

Min

Typ

Max

Units

Error Amplifier

Voltage Gain

400

V/V

Transconductance

300

µA/V

COMP Maximum Output Current

±30

µA

FB Regulation Voltage

875

895

915

mV

FB Input Bias Current

–100

nA

Soft-Start

Soft-Start Current

2

µA

Output Switch On-Resistance

255

mΩ

Switch On Resistance

315

mΩ

210

mΩ

Synchronous Rectifier On Resistance

255

mΩ

Switch Current Limit (Source)

2.5

A

Synchronous Rectifier Current Limit

(Sink)

350

mA

Thermal Shutdown

160

°C

PIN FUNCTIONS

Pin #

Name

Description

1

SS

Soft-Start Input. Place a capacitor from SS to SGND to set the soft-start period. The MP2106

sources 2µA from SS to the soft-start capacitor at startup. As the SS voltage rises, the

feedback threshold voltage increases to limit inrush current during startup.

2

FB

Feedback Input. FB is the inverting input of the internal error amplifier. Connect a resistive

voltage divider from the output voltage to FB to set the output voltage value.

3

COMP

Compensation Node. COMP is the output of the error amplifier. Connect a series RC network

to compensate the regulation control loop.

4

VREF

Internal 2.4V Regulator Bypass. Connect a 10nF capacitor between VREF and SGND to

bypass the internal regulator. Do not apply any load to VREF.

5

RUN

On/Off Control Input. Drive RUN high to turn on the MP2106; low to turn it off. For automatic

startup, connect RUN to VIN via a pullup resistor.

6

BST

Power Switch Boost. BST powers the gate of the high-side N-Channel power MOSFET switch.

Connect a 10nF or greater capacitor between BST and LX.

7

VIN

Internal Power Input. VIN supplies the power to the MP2106 through the internal LDO

regulator. Bypass VIN to PGND with a 10µF or greater capacitor. Connect VIN to the input

source voltage.

8

LX

Output Switching Node. LX is the source of the high-side N-Channel switch and the drain of the

low-side N-Channel switch. Connect the output LC filter between LX and the output.

9

PGND

Power Ground. PGND is the source of the N-Channel MOSFET synchronous rectifier. Connect

PGND to SGND as close to the MP2106 as possible.

10

SGND Signal Ground.