AP7361

1A LOW DROPOUT ADJUSTABLE AND FIXED-MODE

REGULATOR WITH ENABLE

AP7361

Document number: DS33626 Rev. 1 - 2

11 of 15

www.diodes.com

December 2010

© Diodes Incorporated

Application Information (Continued)

Current Limit Protection

When output current at OUT pin is higher than current limit

threshold, the current limit protection will be triggered and

clamp the output current to prevent over-current and to

protect the regulator from damage due to overheating.

Short Circuit Protection

When OUT pin is short-circuit to GND, short circuit

protection will be triggered and clamp the output current to

approximately 200mA. Full current is restored when the

output voltage exceeds 25% of Vout. This feature protects

the regulator from over-current and damage due to

overheating.

Thermal Shutdown Protection

Thermal protection disables the output when the junction

temperature rises to approximately +150°C, allowing the

device to cool down. When the junction temperature

reduces to approximately +130°C the output circuitry is

enabled again. Depending on power dissipation, thermal

resistance,

and

ambient

temperature,

the

thermal

protection circuit may cycle on and off. This cycling limits

the heat dissipation of the regulator, protecting it from

damage due to overheating.

Ultra Fast Start-up

After enabled, the AP7361 is able to provide full power in

as little as tens of microseconds, typically 200µs, without

sacrificing low ground current. This feature will help load

circuitry move in and out of standby mode in real time,

eventually extend battery life for mobile phones and other

portable devices.

Low Quiescent Current

The AP7361, consuming only around 70µA for all input

range, provides great power saving in portable and low

power applications.

Power Dissipation

The device power dissipation and proper sizing of the

thermal plane that is connected to the thermal pad is

critical to avoid thermal shutdown and ensure reliable

operation. Power dissipation of the device depends on

input voltage and load conditions and can be calculated

by:

The maximum power dissipation, handled by the device,

depends on the maximum junction to ambient thermal

resistance,

maximum

ambient

temperature,

and

maximum device junction temperature, which can be

calculated by the equation in the following:

JA

R

)

A

T

-

C

150

(

)

A

T

(max@

D

P

θ

°

+

=