AME, Inc.
AME8821
n
General Description
250mA Hi-PSRR, Low-Quiescent LDO
with In-Rush Current Control
For USB Application
n
Applications
l
Instrumentation
l
Portable Electronics
l
Wireless Devices
l
Cordless Phones
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PC Peripherals
l
Battery Powered Widgets
The AME8821 family of positive, linear regulators fea-
ture low quiescent current (17µA typ.) with low dropout
voltage, making them ideal for battery applications. The
space-saving SOT-25/TSOT-25 packages are attractive
for
“Pocket”
and
“Hand
Held”applications.
These rugged devices have both Thermal Shutdown,
and Current Limitation to prevent device failure under the
“Worst”
operating conditions. In application requires a
low noise regulated supply. The AME8821 family uses
the SR pin to program the output voltage’s slew rate to
control the in-rush current. This is specifically used in
the USB application where large load capacitance is
present at start-up.
The AME8821 also features a logic-enabled sleep mode
to shutdown the regulator, reducing quiescent current to
1µA typical at T
A
= 25
o
C.
The AME8821 is stable with an output capacitance of
4.7µF or larger.
n
Function Block Diagram
V
IN
* ENB or EN
10KΩ
AMP
V
ref
GND
R2
SR
Current Limit
/ Thermal
Protection
R1
V
OUT
* AME8821A: ENB, AME8821B: EN
n
Features
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Guaranteed 250mA Output
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17µA Quiescent Current
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Over-Temperature Shutdown
l
Over-Current Limitation
l
Noise Reduction SR Capacitor
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Power-Saving Shutdown Mode
l
Space-Saving SOT-25/TSOT-25 Packages
l
Factory Pre-set Output Voltages
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Enable pin option
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ENB active low enable
l
EN active high enable
l
All AME's Lead Free Products Meet RoHS
Standards
n
Typical Application
V
IN
1µF
IN
SR
AME8821A
ENB
GND
OUT
0.01µF
+
4.7µF
V
IN
1µF
IN
SR
AME8821B
EN
GND
OUT
0.01µF
+
4.7µF
Rev.A.01
1
AME [ ANALOG MICROELECTRONICS ]
