AAT3242_08 Datasheet, PDF (9/15 Pages) Advanced Analogic Technologies – 300mA/150mA Dual CMOS LDO Linear Regulator

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Functional Block Diagram
INA
ENA
+
Error
Amplifier
-
PRODUCT DATASHEET
AAT3242
300mA/150mA Dual CMOS LDO Linear Regulator
Over-Current
Protection
Over -
Temperature
Protection
-
Voltage
Reference
+
91%
V_REF
OUTA
POKA
INB
ENB
+
Error
Amplifier
-
Over-Current
Protection
Over -
Temperature
Protection
Voltage
Reference
91%
V_REF
OUTB
POKB
-
+
GND
Functional Description
The AAT3242 is a high performance dual LDO regulator
with two Power OK pins. The first regulator (A) sources
300mA of current, while the second (B) regulator can
deliver 150mA. Each regulator has an integrated Power
OK comparator which indicates when the respective out-
put is out of regulation. The POK pins are open drain
outputs, and they are held low when the respective
regulator is in shutdown mode.
The device has independent enable pins to shut down
each LDO regulator for power conservation in portable
products. Forcing EN A/B low (<0.6V) powers down the
regulators and draws a maximum of 1.0μA. The AAT3242
has short-circuit and thermal protection in case of
adverse operating conditions. Device power dissipation
is limited to the package type and thermal dissipation
properties. Refer to the Thermal Considerations section
of this datasheet for details on device operation at max-
imum output current loads.
Applications Information
To assure the maximum possible performance is obtained
from the AAT3242, please refer to the following applica-
tion recommendations.
Input Capacitor
A 1μF or larger capacitor is typically recommended for
C_IN in most applications. A C_IN capacitor is not required
for basic LDO regulator operation; however, if the
AAT3242 is physically located more than three centime-
ters from an input power source, a C_IN capacitor will be
needed for stable operation. C_IN should be located as
closely to the device V_IN pin as practically possible. C_IN
values greater than 1μF will offer superior input line
transient response and will assist in maximizing the
highest possible power supply ripple rejection.
Ceramic, tantalum, or aluminum electrolytic capacitors
may be selected for C_IN. There is no specific capacitor
ESR requirement for C_IN; however, for 300mA LDO regu-
3242.2008.08.1.11
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