MP2110 – 3A SYNCHRONOUS BUCK CONVERTER WITH INPUT CURRENT LIMIT

MP2110 Rev. 1.11

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5

9/26/2014

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PIN FUNCTIONS

Pin #

Name

Description

1, 2

PGND

Power Ground. PGND is internally connected to the source of the low-side N-channel

MOSFET.

3, 4

REGIN

Current limit switch output and buck regulator input. Usually this pin connects to a

large tantalum capacitor as energy reservoir.

5

ENREG

On/Off Control Input of Step-Down Regulator. Active high. Can not be floated.

6

RSET

Input Current Limit setting pin. A resistor from this pin to ground sets the input current

limit.

7

AGND

Analog Ground. Internally connects to the analog ground of control circuitry.

8

ENSYS

Current Limit Switch Enable Input. Active low. It has internal pull down resister.

9

FB

Feedback Input. Connect FB to the center point of the external resistor divider. The

feedback threshold voltage is 0.6V.

10

OUT

Sense pin for output voltage.

11

NTC

Thermistor Input. Connect a resistor from this pin to SYSIN pin and the thermistor

from this pin to ground. Connect to SYSIN to disable the thermal sense function.

12

SYSIN

Supply Voltage. SYSIN supplies power for internal current limit switch. MP2110

operates from a 3.3V to 5.4V continuous input voltage and 12V transient input

voltage.C1 is needed to prevent large voltage spikes at the input. Put C1as close to

the IC as possible.

13, 14

SW

Power Switch Output. Inductor connection to drains of the internal PFET and NFET

switches.

Exposed

Pad

The exposed pad and PGND pin must be connected to the same ground plane.