MP2623 Rev. 1.0

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5

3/16/2012

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PIN FUNCTIONS

Pin #

Name

Description

1

VCC

IC Supply Voltage.

2

NTC

Thermistor Input. Connect a resistor from this pin to VREF33, and the thermistor from this

pin to ground.

3

ACOK

Valid Input Supply Indicator. Open drain output. Add a pull-up resistor. Logic LOW indicates

the presence of a valid input supply.

4

CHGOK

Charging Status Indicator. Open drain output. Add a pull-up resistor. Logic LOW indicates

normal charging. Logic HIGH indicates either a completed charge process or a fault-

suspended process.

5

VREF33

Internal Linear Regulator, 3.3V Reference Output. Bypass to GND with a 1μF ceramic

capacitor.

6

EN

On/Off Control Input.

7

CELLS

for 2-cell operation. Ground for 1-cell operation.

8

COMPV

V-LOOP Compensation. Decouple this pin with a capacitor and a resistor.

9

COMPI

I-LOOP Compensation. Decouple this pin with a capacitor and a resistor.

10

BATT

Positive Battery Terminal.

11

CSP

Battery-Charge Current-Sense–Positive Input. Connect a resistor RS1 between CSP and

BATT. The full charge current is:





mΩ

RS1

200mV

A

I

CHG



.

12

GND

Ground. Voltage reference for the regulated output voltage. Place this node outside of the

path of the switching diode (D2) to the input ground to prevent switching current spikes from

inducing voltage noise.

13

TMR

Set-Safe–Time Period. A 0.1µA current charges and discharges the external capacitor

decoupled to GND. The capacitor value programs the time period.

14

BST

Bootstrap. Requires a charged capacitor to drive the power switch’s gate above the supply

voltage. Connect a capacitor between SW and BST pins to form a floating supply across the

power switch driver.

15

SW

Switch Output.

16

VIN

Regulator Input Voltage. The MP2623 regulates a 5V-to-24V input to a voltage suitable for

spikes from appearing at the input.