1
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
SPX1521
FEATURES
1% 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 LT1521
The SPX1521 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 SPX1521
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.
300mA Low Dropout Voltage Regulator
Now Available in Lead Free Packaging
DESCRIPTION
+
2.2F
+
SPX1521
I
IN
I
G
I
L
5V
IN
OUT
GND
LOAD
I
IN
= I
L
+ I
G
V
OUT
0.1F
TYPICAL APPLICATIONS CIRCUIT
1
2
3
SPX1521
3 Pin TO-263
GND V
IN
V
OUT
2
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
Power Dissipation ........................................................ Internally Limited
Lead Temp. (Soldering, 5 Seconds) ............................................. 260C
Storage Temperature Range ........................................ -65C to +150C
Operating Junction Temperature Range ....................... -40C to +125C
ABSOLUTE MAXIMUM RATINGS
Electrical characteristics at V
IN
= 6V, I
O
= 1mA, C
OUT
= 2.2
F, T
A
= 25
C, unless otherwise specified. Boldface applies over
the full operating temperature range.
PARAMETER
CONDITIONS
TYP
MIN
MAX
UNITS
(Note 2)
3.3V Version
Output Voltage
3.3
3.267
3.333
V
1mA I
L
300mA
3.3
3.217
3.382
Reverse Output Current
V
OUT
= 3.3V, V
IN
= 0V
16
25
A
5.0V Version
Output Voltage
5.0
4.950
5.050
V
1mA I
L
300mA
5.0
4.880
5.120
Reverse Output Current
V
OUT
= 5.0V, V
IN
= 0V
16
25
A
All Voltage Options
Output Voltage
20
100
ppm/C
Temperature Coefficient
(Note1)
Line Regulation
6V V
IN
20V (Note 4)
1.5
20
mV
Load Regulation (Note 3)
I
L
=1 to 300mA
4
20
mV
30
Dropout Voltage (Note 5)
I
L
=1mA
0.13
0.17
V
0.25
I
L
=300mA
0.30
0.55
0.70
Ground Current
I
L
=1mA
100
150
A
I
L
=10mA
350
500
I
L
=50mA
1.5
3
mA
I
L
=100mA
2
6
I
L
=300mA
5
14
Current Limit
V
OUT
=0
330
500
mA
Ripple Rejection
V
IN
-V
OUT
=1V(Avg),
58
50
dB
V
RIPPLE
=0.5Vp-p,
F
RIPPLE
=120Hz, I
LOAD
=150mA
Input Reverse Leakage Current
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
= 25C, V
IN
= 6V, I
L
= 1mA and C
L
= 2.2F.
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 SPX1521 is tested at 25C for I
L
= 1 mA. For T
J
= 125C, 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 1V differential.
Input Supply Voltage ....................................................... -20V to +20V
Shutdown Input Voltage ................................................. -0.6V to +6.5V
ESD Rating .............................................................................. 2kV Min
ELECTRICAL CHARACTERISTICS
3
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
External Capacitors
The stability of the SPX1521 requires a 2.2
F 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 5 or less and
resonant frequency above 500kHz are the most
important parameters in the value of the capaci-
tor. The capacitor value can be increased with-
out limit.
The SPX1521, unlike other low dropout regula-
tors will remain stable and in regulation with no
load in addition to the internal voltage divider.
This feature is especially important in applica-
tions like CMOS RAM keep-alive.
If there is more than 10 inches of wire between
the input and the AC filter capacitor, or if a
battery is used as the input, then a 0.1
F 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 reduce the
regulator bandwidth by increasing the size of
the output capacitor. Increasing the capacitor
from 1
F to 220F only decreases the noise
from 430
V to 160Vrms for a 100kHz band-
width at 5V output.
APPLICATION INFORMATION
Top View
SPX1521
1
3
2
SOT-223 (M3)
Top View
TO-263-3 (T)
1
SPX1521
2
3
Front View
TO-220-3 (U)
SPX1521
1
2
3
Front View
TO-252 (R)
3
2
1
V
IN
GND V
OUT
V
OUT
GND V
IN
V
OUT
GND V
IN
V
OUT
GND
V
IN
PINOUTS
4
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
E
D
L1
b2
e
b
.160 - .190
.000 - .010
Dimensions in inches
3-PIN TO-263
JEDEC TO-263
(AA) Variation
.020 - .039
.015 - .029
.070 - .110
-
- -
A
A1
b
c
D
E
E1
L
L1
L2
MIN NOM MAX
e
.100 BSC
.066
-
.330 - .380
D1
.270 - -
.380 - .420
.245
-
-
H
.575 - .625
.070
L3
.010 BSC
1
2
3
c
C2
A
H
SEATING PLANE
L
0-8
See View C
E/2
View C
GAUGE PLANE
A1
SEATING
PLANE
c
WITH PLATING
BASE METAL
b
SECTION B-B
B
B
3 PIN TO-263
PACKAGE: 3 PIN TO-263
5
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
H1
B
SEATING
PLANE
A1
A
CHAMFER
OPTIONAL
C
A2
A
A
E
P
Q
D
D1
E2
E/2
L
L1
C
C
D
D
b
c
WITH PLATING
BASE METAL
b
CONTACT AREA
1
e
e1
.140 - .190
.020 - .055
Dimensions in
(mm)
3 PIN TO-220
JEDEC TO-220
(AB) Variation
.080 - .115
.015 .027 .040
.045 - .070
.480 - .507
A
A1
A2
b
b2
D1
D2
.380 - .420
E
MIN NOM MAX
c
.014 - .024
D
.560 - .650
.330 - .355
E1
.270
-
.350
E2
- - .030
e
.100 BSC
e1
.200 BSC
H1
.230 - .270
L1
- - .250
L2
- - -
P
.139 - .161
Q
.100 -
.135
3 PIN TO-220
PACKAGE: 3 PIN TO-220
6
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
E1
E1/2
D1
Dimensions in inches
3 PIN TO-252
JEDEC TO-252
(AA) Variation
.018 - .024
c
MIN NOM MAX
A1
- - .005
D1
.205 - -
E1
H
L
L1
L2
.370 - .410
.170 - -
.055 .060 .070
.108 REF
.020 BSC
c
WITH PLATING
BASE METAL
b
CONTACT AREA
SEATING PLANE
C
A1
(L1)
L
c
c
GAUGE PLANE
O
L2
3 PIN TO-252
PACKAGE: 3 PIN TO-252
7
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
PACKAGE: 3 PIN SOT223
See detail
A
C
b2
c
GAUGE
PLANE
SEATING
PLANE
H
A
A1
L
C
0
E
D
1
e
E1
C
C
N
B
B
b2
b
Section C-C
- - 1.80
0.02 - 0.10
Dimensions in (mm)
3 PIN SOT-223
JEDEC TO-261
(AA) Variation
6.50
6.70 7.00 7.30
A
A1
D
E
E1
e
L
MIN NOM MAX
c
0.23
0.30
0.35
6.30
6.70
0
-
10
A2
1.50 1.60 1.70
0.66 0.76 0.84
b
b2
2.90 3.00 3.10
3.30 3.50 3.70
2.30 BASIC
e1
4.60 BASIC
0.75 - -
c
WITH PLATING
BASE METAL
b
Section B-B
3 PIN SOT-223
8
Date: 5/25/04
SPX1521 300mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
Corporation
ANALOG EXCELLENCE
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
ORDERING INFORMATION
Part Number
Accuracy
Output Voltage
Packages
SPX1521M3-3.3
1%
3.3V
3-Pin SOT-223
SPX1521M3-3.3/TR
1%
3.3V
3-Pin SOT-223
SPX1521M3-5.0
1%
5.0V
3-Pin SOT-223
SPX1521M3-5.0/TR
1%
5.0V
3-Pin SOT-223
SPX1521R-3.3
1%
3.3V
3-Pin TO-252
SPX1521R-3.3/TR
1%
3.3V
3-Pin TO-252
SPX1521R-5.0
1%
5.0V
3-Pin TO-252
SPX1521R-5.0/TR
1%
5.0V
3-Pin TO-252
SPX1521T-3.3
1%
3.3V
3-Pin TO-263
SPX1521T-3.3/TR
1%
3.3V
3-Pin TO-263
SPX1521T-5.0
1%
5.0V
3-Pin TO-263
SPX1521T-5.0/TR
1%
5.0V
3-Pin TO-263
SPX1521U-3.3
1%
3.3V
3-Pin TO-220
SPX1521U-5.0
1%
5.0V
3-Pin TO-220
Available in lead free packaging. To order add "-L" suffix to part number.
Example: SPX1521T-3.3/TR = standard; SPX1521T-L-3.3/TR = lead free
/TR = Tape and Reel
Pack quantity is 500 for TO-263 2,000 for TO-252 and 2,500 for SOT-223.
PDF 
ZIP