MP5021 – 12V, 7

MP5021 Rev. 1.1

www.MonolithicPower.com

10

1/30/2013

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2013 MPS. All Rights Reserved.

PIN FUNCTIONS

Pin #

Name

Description

1

EN

Enable Input. Pull this pin below threshold to shut the chip down. Pull it above

threshold or leaving it floating to enable the chip.

2

AUTO

Auto Reset Enable. Float to enable auto reset upon fault removal. Ground to cause

the part to latch off when a fault occurs.

3

ENTM

Enable-Blanking–Time Set. Connect an external capacitor to set the EN blanking

time. Once EN is active, the timer starts and the EN deassertion is blanked. The

switch shuts down in the presence of a fault, but EN-low during blanking has no

effect.

4

TIMER

Timer Set. An external capacitor sets the hot-plug-insertion time delay, fault timeout

period, and restart time.

5

ISET

Current Limit Set. Place a resistor to ground to set the value of the current limit.

6

SS

Soft-Start. An external capacitor connected sets the soft-start time of the output

voltage. The internal circuit controls the slew rate of the output voltage at turn-on.

Float this pin to set the soft-start time at its minimum of 1ms.

7

GND

Ground

8

IMON

Output Current Monitor. Provides a voltage proportional to the current flowing

through the power device. Place a resistor to ground to set the gain.

9

FLTB

Fault Bar. This is an open drain output that drives to ground when an over-current or

a thermal shutdown occurs. Pull-up to an external power supply through a 100kΩ

resistor.

10

PG

Power Good. This is an open drain output. Pull-up to external power supply through

100kΩ resistor. High = power-good. Low indicates output is outside UVLO/OVLO

window. PG starts to work when the pull-up supply is enabled, even if the VIN and

EN are still disabled.

11

FB

Feedback. An external resistor divider from the output sets the output voltage where

the PG pin switches. The rising threshold is 0.6V with 65mV hysteresis.

12

PD

Output Discharge. Connect to the output to provide a 500Ω load to discharge the

output when the part is disabled. No Connect disables this function.

13-20

OUT

Output. Voltage controlled by the IC. Place a Schottky diode between the OUT pin

and GND pin.

21-22,

Exposed

Pads

VIN

Input Power Supply.