1
Date: 5/25/04
SPX1129 400mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
SPX1129
DESCRIPTION
FEATURES
1% Output Accuracy 3.3V, 5V,
at 500mA Output
Very Low Quiescent Current
0.42V Dropout Voltage at 400mA
Extremely Tight Load and Line Regulation
Current & Thermal Limiting
Reverse Battery Protection
Equivalent Replacement For LT1129
APPPLICATIONS
Power Supply
Communications Equipment
Computers and Peripherals
The SPX1129 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 SPX1129
features very low quiescent current and very low dropout voltage of 0.42 volts. This includes a tight initial
tolerance of
1% max, and a very low output temperature coefficient, making the SPX1129 useful as a low-
power voltage reference.
The SPX1129 is offered in a SOT-223, TO-220, TO-252 & TO-263 3 lead packages.
400mA Low Dropout Voltage Regulator
+
2.2F
+
SPX1129
I
IN
I
G
I
L
5V
IN
OUT
GND
LOAD
I
IN
= I
L
+ I
G
V
IN
0.1F
Fixed +5V Regulator Circuit..
TYPICAL APPLICATION CIRCUIT
GND
V
OUT
V
IN
3
2
1
SPX1129
3 Pin TO-220
1
2
3
SPX1129
3 Pin TO-263
GND
V
IN
V
OUT
V
OUT
GND
V
IN
TO-252
3
2
1
SPX1129
1
2
3
SPX1129
3 Pin TO-263
GND
V
IN
V
OUT
Now Available in Lead Free Packaging
2
Date: 5/25/04
SPX1129 400mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
Power Dissipation ........................................................ Internally Limited
Lead Temp. (Soldering, 5 Seconds) ............................................. 260
C
Storage Temperature Range ........................................ -65
C to +150
C
Operating Junction Temperature Range ....................... -40
C to +125
C
ELECTRICAL CHARACTERISTICS
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
400mA
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
400mA
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
10
mV
Load Regulation (Note 3)
I
L
=1 to 400mA
6
20
mV
30
Dropout Voltage (Note 5)
I
L
=1mA
0.13
0.17
V
0.25
I
L
=400mA
0.42
0.55
0.70
Ground Current
I
L
=1mA
100
200
A
I
L
=10mA
350
500
I
L
=50mA
1.5
3
mA
I
L
=100mA
2
6
I
L
=400mA
7
25
Current Limit
V
OUT
=0
330
800
mA
Ripple Rejection
V
IN
-V
OUT
=1V(Avg),
58
50
dB
V
RIPPLE
=0.5Vp-p, F
RIPPLE
=120Hz,
I
LOAD
=400mA, T
J
= 25
C
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
= 25
C, V
IN
= 6V, I
L
= 1mA and C
L
= 2.2
F.
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 SPX1129 is tested at 25
C for I
L
= 1 mA. For T
J
= 125
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 1V differential.
Input Supply Voltage ....................................................... -20V to +20V
ESD Rating .............................................................................. 2kV Min
ABSOLUTE MAXIMUM RATINGS
3
Date: 5/25/04
SPX1129 400mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
External Capacitors
The stability of the SPX1129 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 SPX1129, 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 tanta-
lum 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 decreases the noise from
430
V to 160V rms for a 100kHz bandwidth
at 5V output.
APPLICATION INFORMATION
4
Date: 5/25/04
SPX1129 400mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
E
M
P
W
L
-A-
N
R
B
S
H
A
K
G
D
C
DIMENSIONS
in inches
SYMBOL
MIN
MAX
A
.396
0.406
B
0.326
0.336
C
0.170
0.180
D
0.026
0.036
E
0.045
0.055
G
0.100 REF
0.100 REF
H
0.580
0.620
K
0.055
0.066
L
.000
.010
M
0.098
0.108
N
.017
.023
P
.090
.110
R
0
8
S
.095
.105
U
.30 REF
.30 REF
V
.305 REF
.305 REF
W
.010
.010
V
U
TERMINAL 8
3 Pin TO-263
PACKAGE: 3 PIN TO-253
5
Date: 5/25/04
SPX1129 400mA Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
3 Pin TO-220
D
J1
C1
(5X)
E
Q
H1
V
P
E-PIN
e3
L
e
e1
b1
R
DIMENSIONS
in inches
SYMBOL
MIN
MAX
A
0.160
0.190
b
0.025
0.040
C1
0.015
0.022
D
0.560
0.590
E
0.385
0.415
e
0.090
0.110
e1
0.190
0.210
e3
0.045
0.055
F
0.045
0.055
H1
0.234
0.258
J1
0.090
0.115
P
0.146
0.156
Q
0.103
0.113
L
0.540
0.560
3
typ
7
typ
b1
0.450
0.060
R
0.243 REF
6.170 REF
U
0.300 REF
7.620 REF
V
0.240 REF
6.100 REF
F
A
CL
PACKAGE: 3 PIN TO-220
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