APL1565A View Datasheet(PDF) - Anpec Electronics

Part Name

Description

Manufacturer

APL1565A

1A Low Dropout, Fast Response Fixed Voltage Regulator

Anpec Electronics 

APL1565A

Application Information

Capacitor Selection and Regulator

Stability

The APL1565A use at least a 4.7µF capacitor on the

input. This capacitor can use Aluminum, Tantalum or

Ceramic capacitors. Input capacitor with large val-

ues and low ESR provide better PSRR and line-tran-

sient response. The output capacitor also can use

Aluminum, Tantalum or Ceramic capacitors, and a

minimum value of 10µF and ESR above 0.06Ω is

recommended. A larger output capacitor can reduce

noise and improve load-transient response, stability

and PSRR.

Load-Transient Considerations

The APL1565A load-transient response graphs in

typical characteristics show the transient response.

A step change in the load current from 0mA to 1A at

1us will cause a 100mV transient spike. Larger out-

put capacitor and lower ESR can reduce transient

spike.

Reverse Current Protection

The APL1565A have an internal reverse protection,

it does not need an external schottky diode to con-

nect the regulator input and output. If the output volt-

age is forced above the input voltage by more than

11mV, the IC will be shutdown and the ground pin

current is below 0.1uA.

Current Limit

The APL1565A have a current limit protection. The

ouptut voltage will drop close to zero volt, when load

current reaches the limit, and then the load current

will be limited at 150mA after output voltage is below

0.7V. When the load current back to the value where

limiting started, the output voltage and current will

return to normal value. When output is shorted to

ground, the APL1565/A will keep short circuit current

at 150mA .

Input-Output (Dropout)Voltage

The minimum input-output voltage difference

(dropout) determines the lowest usable supply

voltage. In battery-powered systems, this will deter-

mine the useful end-of-life battery voltage. Because

the APL1565A use a p-channel MOSFET pass

transistor, the dropout voltage is a function of drain-

to-source on-resistance (RDS(ON)) multiplied by the load

current.

Thermal Protection

Thermal protection limits total power dissipation in

the device. When the junction temperature exceeds

TJ=+150J, the thermal sensor generates a logic sig-

nal to turn off the pass transistor and allows IC to

cool. When the IC’s junction temperature is down by

10J, the thermal sensor will turn the pass transistor

on again, resulting in a pulsed output during continu-

ous thermal protection. Thermal protection is de-

signed to protect it in the event of fault conditions.

For continuous operation, do not exceed the abso-

lute maximum junction temperature of TJ=+150J.

Copyright  ANPEC Electronics Corp.

4

Rev. A.3 - Oct., 2002

www.anpec.com.tw

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