US1010-25
2-1
Rev. 1.1
10/30/00
TYPICAL APPLICATION
TYPICAL APPLICATION
DESCRIPTION
DESCRIPTION
The US1010-25 is a low dropout three terminal fixed out-
put regulator with minimum of 1A output current capabil-
ity. This product is specifically designed to provide well
regulated supply for low voltage IC applications as well
as generating clock supply for the PC applications. The
US 1010 is guaranteed to have <1.3V drop out at
full load current making it ideal to provide well regu-
lated with 3.8V input supply. The US1010 is specifically
designed to be stable with low cost Aluminimum ca-
pacitors while still maintains stability with low ESR tan-
talum caps as well.
FEATURES
FEATURES
Guaranteed < 1.3V Dropout at Full Load
Current
Fast Transient Response
1% Voltage Reference Initial Accuracy
Built-in Thermal Shutdown
Available in SOT-223 & D-PAK and a new Power
Flex Surface Mount Packages
APPLICATIONS
APPLICATIONS
Low Voltage IC supply Applications
PC Clock Supply Voltage
1A LOW DROPOUT POSITIVE
FIXED OUTPUT REGULATOR
Typical Application of US1010-25 in a 5V to 2.5V regulator .
PRELIMINARY DATASHEET
PACKAGE ORDER INFORMATION
PACKAGE ORDER INFORMATION
Tj (
C) 2 PIN PLASTIC 3 PIN PLASTIC 2 PIN PLASTIC
TO252 (D) SOT223 (Y) POWER FLEX (P)
0 TO 150 US1010-25CD US1010-25CY US1010-25CP
5V
2.5V / 1A
C1
10uF
C2
10uF
US1010-25
1010-25app1-1.0
3
1
2
Vin
Vout
Gnd
US1010-25
2-2
Rev. 1.1
10/30/00
ABSOLUTE MAXIMUM RATINGS
ABSOLUTE MAXIMUM RATINGS
Input Voltage (Vin) .................................................................. 7V
Power Dissipation ............................................ Internally Limited
Storage Temperature Range .............................. -65
C TO 150
C
Operating Junction Temperature Range .................. 0
C TO 150
C
PACKAGE INFORMATION
PACKAGE INFORMATION
2 PIN PLASTIC TO252 ( D )
3 PIN PLASTIC SOT223 ( Y ) 2 PIN POWER FLEX ( P )
JA
=70
C/W for 0.5" Square pad
JA
=90
C/W for 0.4" Square pad
JA
=70
C/W for 0.5" Square pad
ELECTRICAL SPECIFICATIONS
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over, Cin=1uF, Vin=5V,Cout=10uF, and Tj=0 to 125
C.Typical
values refer to Tj=25
C.
PARAMETER
SYM
TEST CONDITION
MIN
TYP
MAX
UNITS
Output Voltage
Vo
Io=10mA,Tj=25
C
2.475 2.500
2.525 V
Io=10mA
2.450 2.500
2.550
Line Regulation
Io=10mA,4.75V<Vin<7V
7
mV
Load Regulation (Note 1)
10mA<Io<1A
17
mV
Dropout Voltage (Note 2)
Io=1A
1.3
V
Current Limit
dVo=100mV
1.1
A
Thermal Regulation
30 mS PULSE, Io=1A
0.01
0.02
%/W
Ripple Rejection
f=120HZ ,Co=25uF Tan
Io=0.5A
60 70 dB
Temperature Stability
Io=10mA
0.5
%
Long Term Stability
Tj=125
C,1000 Hrs
0.3
1
%
RMS Output Noise
Tj=25
C 10hz<f<10khz
0.003
%Vo
Note 1 : Low duty cycle pulse testing with Kelvin connections are required in order to maintain accurate data.
Note 2 : Drop-out voltage is defined as the minimum differential voltage between Vin and Vout required to maintain
regulation at Vout. It is measured when the output voltage drops 1% below its nominal value.
1
4
3
FRONT VIEW
Gnd
Tab is
Vout
Vin
3
1
2
TOP VIEW
Gnd
Vout
Vin
Tab is
Vout
FRONT VIEW
1
4
3
Tab is
Vout
Gnd
Vin
US1010-25
2-3
Rev. 1.1
10/30/00
PIN DESCRIPTIONS
PIN DESCRIPTIONS
Pin Description
Gnd pin. This pin must be connected to GND plane using a low inductance short connec-
tion.
The output of the regulator. This pin is also connected to the tab of the package. An
output capacitor must be connected to this pin to insure stability of the regulator.
Input pin of the regulator.
PIN# PIN SYMBOL
1
Gnd
2
Vout
3
Vin
BLOCK DIAGRAM
BLOCK DIAGRAM
Figure 1 - Simplified block diagram of the US1010-25
Vin 3
1010-25blk1-1.0
1 Gnd
2 Vout
THERMAL
SHUTDOWN
CURRENT
LIMIT
1.25V
+
+
PDF 
ZIP