IMP37
P
OWER
M
ANAGEMENT
Key Features
Low Dropout Positive
Voltage Regulators
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Low Dropout Voltage
– 0.8V maximum at 100mA
– 0.95V maximum at 800mA
– 20% lower dropout voltage than “1117”
LDO regulators
Guaranteed Low Dropout Voltage at Multiple
Current Levels
1% Trimmed 2.5V, 3.0V and 3.3V Outputs
Reduced Quiescent Current: 75µA Maximum
Short Circuit and Thermal Protection
Space Saving SOT-223 Surface Mount Package
“1117” Pin Compatible
– 800mA
– 2.5V, 3.0V and 3.3V Output
The IMP37 series of Low Dropout (LDO) three-terminal voltage regula-
tors feature guaranteed low dropout voltages at currents up to 0.8A. The
IMP37 regulator family dropout voltage is guaranteed to be 0.95V or
lower at 0.8A. At 100mA, the maximum dropout voltage is 0.8V.
Compared with “1117” type LDOs, the IMP37 has a 20% lower dropout
voltage.
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◆
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Three fixed output voltages are offered: 2.5V, 3.0V and 3.3V. Output volt-
ages are factory trimmed to within 1% of the nominal value.
In addition to low dropout voltages, the IMP37 family features greatly
reduced quiescent operating current. The 75µA maximum specification
represents an over 100 times improvement over competitive devices.
Applications
Devices are short circuit protected, and a thermal protection circuit shuts
the regulator off should the junction temperature exceed 165°C.
◆ High-efficiency linear power supplies
◆ Post regulator for switching supplies
◆ 5V to 3.3V linear regulators
◆ USB hubs
The IMP37 is available in low-profile plastic SOT-223 and TO-263
packages and are pin compatible with fixed “1117” devices.
◆ Battery chargers
◆ Routers, ISDN/DSL modems
Block Diagram
RCS
3
2
Input
Out
(Tab)
IMP37
Error
Amp
+
–
+
–
Current
Thermal
Limit
+
–
Ref
Protection
1
GND
37_01.eps
©
1999 IMP, Inc.
408-432-9100/www.impweb.com
1
IMP [ IMP, INC ]
