AAT3221/2

150mA NanoPower™ LDO Linear Regulator

PRODUCT DATASHEET

8

3221.2007.11.1.12

www .analogictech.com

Functional Description

The AAT3221 and AAT3222 are intended for LDO regula-

tor applications where output current load requirements

range from no load to 150mA. The advanced circuit

design of the AAT3221/2 has been optimized for very low

quiescent or ground current consumption, making it

ideal for use in power management systems for small

battery-operated devices. The typical quiescent current

level is just 1.1μA. AAT3221/2 devices also contain an

enable circuit which has been provided to shut down the

LDO regulator for additional power conservation in por-

table products. In the shutdown state, the LDO draws

less than 1μA from input supply.

The LDO also demonstrates excellent power supply rip-

ple rejection (PSRR) and load and line transient response

characteristics. The AAT3221/2 high performance LDO

regulator is especially well suited for circuit applications

that are sensitive to load circuit power consumption and

extended battery life.

The LDO regulator output has been specifically optimized

to function with low-cost, low-ESR ceramic capacitors.

However, the design will allow for operation with a wide

range of capacitor types.

The AAT3221/2 has complete short-circuit and thermal

protection. The integral combination of these two inter-

nal protection circuits gives the AAT3221/2 a compre-

hensive safety system to guard against extreme adverse

operating conditions. Device power dissipation is limited

to the package type and thermal dissipation properties.

Refer to the Thermal Considerations section of this docu-

ment for details on device operation at maximum output

load levels.

Functional Block Diagram

Over-Current

Protection

Over-Temperature

Protection

IN

EN

OUT

GND