AP7362

1.5A, LOW QUIESCENT CURRENT, FAST TRANSIENT

ULTRA-LOW DROPOUT LINEAR REGULATOR

AP7362

Document number: DS35058 Rev. 2 - 2

9 of 13

www.diodes.com

June 2011

© Diodes Incorporated

Application Information (cont.)

ON/OFF Input Operation

The AP7362 is turned on by setting the EN pin high, and

is turned off by pulling it low. If this feature is not used,

the EN pin should be tied to IN pin to keep the regulator

output on at all time. To ensure proper operation, the

signal source used to drive the EN pin must be able to

swing above and below the specified turn-on/off voltage

thresholds listed in the Electrical Characteristics section

Short Circuit 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.

Thermal Shutdown Protection

Thermal protection disables the output when the junction

temperature rises to approximately +170°C, allowing the

device to cool down. When the junction temperature

reduces to approximately +160°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.

Low Quiescent Current

The AP7362, consumes only around 0.5mA for all input

voltage range and load currents, this provides great power

saving in portable and low power applications.

Output Noise

This is the integrated value of the output noise over a

specified frequency range. Input voltage and output load

current are kept constant during the measurement.

Results are expressed in

μVrms or μV √Hz.

The AP7362 is a low noise regulator and needs no

external noise reduction capacitor. Output voltage noise is

typically 100

μVrms overall noise level between 100 Hz

and 100 kHz

Noise is specified in two ways:

Output noise density is the RMS sum of all noise

sources, measured at the regulator output, at a specific

frequency (measured with a 1Hz bandwidth). This type of

noise is usually plotted on a curve as a function of

frequency.

Output noise voltage is the RMS sum of spot noise over

a specified bandwidth. Spot noise is measured in units

μV/√Hz or nV/√Hz and total output noise is measured in

μV(rms). The primary source of noise in low-dropout

regulators is the internal reference.

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 junction to ambient thermal resistance,

and

maximum

ambient

temperature,

which

can

be

calculated by the equation in the following:

JA

R

)

A

T

-

C

150

(

P

max

_

D

θ

°

+

=

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100

120

FREQUENCY(Hz)

-80

-60

-40

-20

0

20

40

60

80

100

120

140

100

1k

10k

100k

1M

GAIN

PHASE

Gain-Bandwidth Plot for no Load