AP2303 datasheet(9/15 Pages) DIODES

9 / 15 page

AP2303

Document number: DS36546 Rev. 3 - 2

9 of 15

www.diodes.com

September 2014

AP2303

A Product Line of

Diodes Incorporated

Application Information

1. Input Capacitor

The input capacitor of VIN should be placed to VIN pin as close as possible. Use a low ESR, 10µF or larger MLCC capacitor to provide surge

current during load transient.

The input capacitor for VCNTL is recommended to be 0.47µF or larger to decouple

the supply voltage of AP2303’s control circuitry.

2. Output Capacitor

The output capacitor is recommended with a 10µF or higher MLCC capacitor which will be sufficient at full temperature range. An aluminum

electrolytic capacitor with low ESR also should be larger than 10µF. The output capacitor should be placed to VOUT pin as close as possible.

3. Reference Voltage

A reference voltage is applied to the VREFEN pin by a resistor divider between VIN and GND pins. And a 0.1µF to 1µF bypass capacitor is

preferred to form a low-pass filter to reduce the noise from VIN. More capacitance and large resistance will increase the start-up time after VIN

power-up.

4. Thermal Consideration

There’s an internal thermal protection circuitry of AP2303 to protect device during overload conditions. For continuous operation, make sure not to

exceed the operating junction temperature range of +125°C. The power dissipation definition in device is:

PD=(VIN - VOUT)xIOUT+VINxIQ

The maximum power dissipation depends on the thermal resistance of IC package, PCB layout and the surrounding airflow. The maximum power

dissipation can also be calculated as:

PD(MAX) = (TJ(MAX)-TA)/θJA

The maximum power dissipation for PSOP-8 package at TA = +25°C can be calculated as:

PD(MAX) = (125°C-25°C) / (80°C/W) = 1.25W

AP2303 Datasheet(PDF) 9 Page - Diodes Incorporated