Solved by
SPX1521
TM
300mA Low Dropout Voltage Regulator
FEATURES
■
% Output Accuracy 3.3V, 5V,
at 300mA Output
■
Very Low Quiescent Current
■
0.3V (Typ.) Dropout Voltage at 300mA
■
Extremely Tight Load and Line Regulation
■
Current & Thermal Limiting
■
Reverse Battery Protection
■
Equivalent Replacement For LT52
SPX1521
3 Pin TO-263
1
2
3
V
OUT
GND V
IN
Now Available in Lead Free Packaging
DESCRIPTION
The SPX52 is a low power voltage regulator. This device is an excellent choice for use in battery-
powered applications such as cordless telephones, radio control systems, and portable computers.
The SPX52 features very low quiescent current and very low dropout voltage. This includes a tight
initial tolerance of ±1% max, and very low output temperature coefficient, making the SPX1521 useful
as a low-power voltage reference.
The SPX1521 is offered in 3 pin TO-252, SOT-223, TO-220 & TO-263 packages.
TYPICAL APPLICATIONS CIRCUIT
V
OUT
I
IN
IN
OUT
5V
I
L
SPX1521
0.1µF
+
GND
+
2.2µF
LOAD
I
IN
= I
L
+ I
G
I
G
Date: Oct4-06
SPX52 300mA Low Dropout Voltage Regulator
© 2006 Sipex Corporation
Power Dissipation ........................................................ Internally Limited
Lead Temp. (Soldering, 5 Seconds) ............................................. 260°C
.
Storage Temperature Range ........................................ -65°C to +50°C
.
Operating Junction Temperature Range ...................... -40°C to +25°C
Input Supply Voltage................................................... -20V to +20V
ABSOLUTE MAXIMUM RATINGS
Shutdown Input Voltage...................................................-0.6V to +6.5V
ESD Rating ...............................................................................2kV
Min
.
Electrical characteristics at V
IN
= 6V, I
O
= mA, C
OUT
= 2.2µF, T
A
= 25°C, unless otherwise specified.
Boldface applies over the full operating temperature range.
PARAMETER
3.3V Version
Output Voltage
Reverse Output Current
5.0V Version
Output Voltage
Reverse Output Current
All Voltage Options
Output Voltage
Temperature Coefficient
Line Regulation
Load Regulation (Note 3)
Dropout Voltage (Note 5)
Ground Current
Current Limit
Ripple Rejection
Input Reverse Leakage Current
CONDITIONS
(Note 2)
mA
≤ I
L
≤ 300mA
TYP
MIN
MAX
ELECTRICAL CHARACTERISTICS
UNITS
3.3
3.3
6
5.0
5.0
6
20
1.5
4
0.3
0.30
100
350
1.5
2
5
330
58
3.267
3.217
4.950
4.880
3.333
3.382
25
5.050
5.120
25
100
20
20
30
0.7
0.25
0.55
0.70
150
500
3
6
14
500
V
µA
V
µA
ppm/°C
mV
mV
V
V
OUT
= 3.3V, V
IN
= 0V
mA
≤ I
L
≤ 300mA
V
OUT
= 5.0V, V
IN
= 0V
(Note1)
6V ≤ V
IN
≤ 20V (Note 4)
I
L
= to 300mA
I
L
=mA
I
L
=300mA
I
L
=mA
I
L
=0mA
I
L
=50mA
I
L
=00mA
I
L
=300mA
50
µA
mA
V
OUT
=0
V
IN
-V
OUT
=V(Avg),
V
RIPPLE
=0.5Vp-p,
mA
dB
F
RIPPLE
=20Hz, I
LOAD
=50mA
V
IN
= -20V, V
OUT
=0V
1.0
mA
Note 1:
Output or reference voltage temperature coefficients defined as the worst case voltage change divided
by the total temperature range.
Note 2:
Unless otherwise specified all limits are guaranteed for T
j
= 25°C, V
IN
= 6V, I
L
= mA and C
L
= 2.2µF.
Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle.
Changes
in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 4: Line regulation for the SPX52 is tested at 25°C for I
L
= mA. For T
J
= 25°C, line regulation is
guaranteed by design.
Note 5:
Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV
below its nominal value measured at V differential.
Date: Oct4-06
SPX52 300mA Low Dropout Voltage Regulator
© 2006 Sipex Corporation
2
APPLICATION INFORMATION
External Capacitors
The stability of the SPX52 requires a
2.2µF or greater capacitor between output
and ground. Oscillation could occur without
this capacitor. Most types of tantalum or
aluminum electrolytic works fine here. For
operations of below -25°C solid tantalum is
recommended since the many aluminum
types have electrolytes that freeze at about
-30°C. The ESR of about 5Ω or less and
resonant frequency above 500kHz are the
most important parameters in the value of
the capacitor. The capacitor value can be
increased without limit.
The SPX1521, unlike other low dropout
regulators will remain stable and in regula-
tion with no load in addition to the internal
voltage divider. This feature is especially
important in applications like CMOS RAM
keep-alive.
If there is more than 0 inches of wire be-
tween the input and the AC filter capacitor,
or if a battery is used as the input, then a
0.µF tantalum or aluminum electrolytic
capacitor should be placed from the input
to the ground.
Reducing Output Noise
It may be an advantage to reduce the AC
noise present at the output. One way is to re-
duce the regulator bandwidth by increasing
the size of the output capacitor. Increasing
the capacitor from µF to 220µF only de-
creases the noise from 430µV to 60µVrms
for a 100kHz bandwidth at 5V output.
Note: Tab is connected to GND
SOT-223 (M3)
TO-263-3 (T)
TO-220-3 (U)
PINOUTS
TO-252 (R)
3
V
IN
GND
V
OUT
SPX1521
1
2
3
1
SPX1521
2
3
SPX1521
1
2
3
2
1
V
IN
GND V
OUT
Top View
Front View
V
OUT
GND V
IN
Top View
Thermal Resistance (Theta JA)
SOT-223 ------62.3ºC/W
TO-262 ------3.4ºC/W
TO-220 ------29.4ºC/W
TO-252 ------50.0ºC/W
V
OUT
GND V
IN
Front View
Date: Oct4-06
SPX52 300mA Low Dropout Voltage Regulator
© 2006 Sipex Corporation
3
PACKAGE: 3 PIN TO-263
Date: Oct4-06
SPX52 300mA Low Dropout Voltage Regulator
© 2006 Sipex Corporation
4
PACKAGE: 3 PIN TO-220
Date: Oct4-06
SPX52 300mA Low Dropout Voltage Regulator
© 2006 Sipex Corporation
5
