MP2326 Rev. 1.1

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10

1/28/2016

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PIN FUNCTIONS

Package

Pin #

Name

Description

1,12

GND

System Ground. GND is the reference ground for the regulated output voltage, and it

requires special consideration during PCB layout (see the recommended “PCB Layout

Guidelines” section on page 19).

2, 13

SW

Switch Output. Connect SW using wide PCB traces.

3, 14

VIN

Supply Voltage. The MP2326 operates from a +3.9V to +19V input rail. C1 is needed to

decouple the input rail. Use wide PCB traces and multiple vias to make the connection.

4

FREQ/MODE

Frequency Set during CCM Operation. Connect a resistor to VIN to set the switching

frequency; the part works in forced PWM mode. Connect a resistor to GND to set the

switching frequency; the part works in auto PFM/PWM mode. Do NOT float

FREQ/MODE.

5

PG

Power Good Output. The output of PG is an open drain that goes high if the output

voltage is higher than 90% of the nominal voltage. There is a 40µs delay when FB ≥

90% and when PG goes high.

6

SS

Soft-Start. Connect a capacitor across SS and GND to set the soft-start time to avoid a

start-up inrush current.

7

FB

Feedback. FB sets the output voltage when connected to the tap of an external resistor

divider that is connected between the output and GND.

8

CR

Internal Ramp Adjust. Connect a capacitor from VOUT to CR to adjust the internal ramp

amplitude. This can be used to improve the transient performance.

9

EN

Enable/Disable Control. EN = 1 to enable the MP2326. For automatic start-up, connect

EN to VIN with a pull-up resistor.

10

BST

Bootstrap. BST requires a capacitor connected between SW and BST to form a floating

supply across the high-side switch driver.

11

VCC

Internal Bias Supply. Internal 5V LDO output. Decouple with a 1µF ceramic capacitor as

close to VCC as possible.