MP8867 – SYNCHRONOUS STEP-DOWN CONVERTER

MP8867 Rev.1.01

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12

2/21/2017

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PIN FUNCTIONS

QFN14

PIN#

Name

Description

1

BST

Bootstrap. Requires a capacitor between SW and BST to form a floating supply

across the high-side switch driver.

2

SW

Switch output. Connect using a wide PCB trace.

3

SCL

I

4

SDA

I

5

EN/SYNC

EN/SYNC high to enable the MP8867. EN/SYNC has an internal 5.4µA pull-up

current of 5V, so the MP8867 can start up automatically when EN/SYNC is floating.

Apply an external clock to EN/SYNC to change the switching frequency.

6

A0

I

set a different address.

7

PG

Power good indication. PG is an open-drain structure. PG switches low if the output

voltage is out of the regulation window. PG indicates UV conditions only.

8

PGND

System power ground. PGND is the reference ground of the regulated output voltage.

PGND requires special consideration during PCB layout. Connect to ground plane with

copper traces and vias.

9

VIN

Supply voltage. The MP8867 operates on a 4.5V to 17V input rail. VIN requires a

ceramic capacitor to decouple the input rail. Connect using a wide PCB trace.

10

VOUT

Sense input of the output voltage. Connect VOUT to the positive loading terminal.

11

FB

Feedback. Connect FB to the tap of an external resistor divider from the output to

GND to set the output voltage in the FB control loop.

12

SS

Soft start. Connect a capacitor from SS to ground to set the soft-start time.

13

VCC

Internal LDO regulator output. Decouple with a 0.47µF capacitor.

14

AGND

Signal ground. AGND is not connected directly to system ground internally. Make

sure AGND connects to system ground in the PCB layout.