A6300
AiT Semiconductor Inc.
www.ait-ic.com
LOW DROPOUT VOLTAGE REGULATOR
300mA CMOS WITH ENABLE PIN
Reverse Current Path
The power transistor used in the A6300 has an inherent diode connected between the regulator input and
output (see Fig.1). If the output is forced above the input by more than a diode-drop, this diode will become
forward biased and current will follow from the VOUT terminal to VIN. The diode will also be turned on the by
abruptly stepping the input voltage to a value below the output voltage. To prevent regulator mis-operation, a
Schottky diode should be used in any applications where input/output voltage conditions can cause the
internal diode to be turned on (see fig.2). As shown, the Schottky diode is connected in parallel with the
internal parasitic diode and prevents it from being turned on by limiting the voltage drop across it to about
0.3V <100mA to prevent damage to the part.
Fig.1
Fig.2
Operating Region and Power Dissipation
The A6300 maximum power dissipation depends of the thermal resistance of the case and circuit board, the
temperature difference between the die junction and ambient air, and the rate of airflow.
The power dissipation across the device is:
P = IOUT (VIN – VOUT).
The maximum power dissipation is :
PMAX = (TJ –TA) / θJA.
Where TJ – TA is the temperature difference between the A6300 die junction and surrounding environment,
θJA is the thermal resistance from the junction to the surrounding environment.
The GND pin of the A6300 performs the dual function of providing an electrical connection to ground and
channeling heat away.
Connect the GND pin to ground using a large pad or ground plane.
REV1.4
- JUN 2006 RELEASED, FEB 2015 UPDATED -
15
AITSEMI [ AiT Semiconductor ]
