MP5003 – 3.3V, 1A-3A PROGRAMMABLE CURRENT LIMIT SWITCH WITH AUTO ENABLE

MP5003 Rev. 0.921

www.MonolithicPower.com

10

2/29/2012

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© 2012 MPS. All Rights Reserved.

There are 4 types of faults, and each fault has a

direct and indirect effect on the Enable/Fault pin

and the internal fault flag. In a typical application

where there are multiple MP5003 chips in a

system, the enable/fault lines are typically

connected together.

UNDER VOLTAGE LOCK OUT OPERATION

If the supply (input) is below the UVLO threshold,

the output is disabled, and the fault line is driven

low.

When the supply goes above the UVLO

threshold, the output is enabled and the

Enable/fault

pin

is

released.

When

the

Enable/fault pin is released it will be pulled high

by a 25uA current source. No external pull up

resistor is required. In addition, the pull up

voltage is limited to 5 volts.

Table 3—Fault Function Influence in Application

Fault description

Internal action

Effect on Fault

Pin

Effect on

Flag

Effect on secondary Part

Short/over current

Limit current

none

none

none

Under Voltage

Output is turned off

Internally drives

Enable/Fault pin to

Logic low

Flag is

reset

Secondary part output is

disabled, and fault flag is

reset.

Over Voltage

Limit output voltage

None

None

None

Thermal Shutdown

Shutdown part. The

part retries to start

up automatically

Internally drives

Enable/Fault pin

to low level, and

after part cools

down, Enable/Fault

pin will be pulled

high

Flag is Set

at thermal

shut down,

and is set

to high

after auto

start up.

Secondary part output is

disabled when thermal

shut down, and is enabled

after MP5003 auto start up.