AAT3220 Datasheet, PDF (13/16 Pages) Advanced Analogic Technologies – 150mA NanoPower™ LDO Linear Regulator

AAT3220
150mA NanoPower™ LDO Linear Regulator
P_D(total) = P_D(100mA) + P_D(150mA)
P_D(total) = 110.2mW + 14.8mW
P_D(total) = 125.0mW
The maximum power dissipation for the AAT3220
operating at an ambient temperature of 85°C is
200mW. The device in this example will have a
total power dissipation of 125.0mW. This is well
with in the thermal limits for safe operation of the
device.
Printed Circuit Board Layout
Recommendations
In order to obtain the maximum performance from
the AAT3220 LDO regulator, very careful attention
must be paid in regard to the printed circuit board
layout. If grounding connections are not properly
made, power supply ripple rejection and LDO regu-
lator transient response can be compromised.
The LDO Regulator external capacitors C_IN and
C_OUT should be connected as directly as possible
to the ground pin of the LDO Regulator. For maxi-
mum performance with the AAT3220, the ground
pin connection should then be made directly back
to the ground or common of the source power sup-
ply. If a direct ground return path is not possible
due to printed circuit board layout limitations, the
LDO ground pin should then be connected to the
common ground plane in the application layout.
3220.2001.09.1.0
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