1
Date: 5/25/04
SPX29302A 3Amp LDO Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
3A High Current, Low Dropout Voltage Regulator
Adjustable, Fast Response Time
SPX29302A
FEATURES
Adjustable Output Down To 1.25V
1% Output Accuracy
Output Current of 3A
Low Dropout Voltage of 370mV @ 3A
Extremely Fast Transient Response
Reverse-Battery Protection
Zero Current Shutdown (5 pin version)
Standard TO-220 and TO-263
Packages
The SPX29302A is a 3A, highly accurate voltage regulator with a low drop out voltage of
370mV (typical) @ 3A. These regulators are specifically designed for low voltage applications
that require a low dropout voltage and a fast transient response. Fault protection features
include over-current, reverse battery, and positive and negative voltage transients. On-Chip
trimming adjusts the reference voltage to 1% initial accuracy.
The SPX29302A is offered in 5-pin TO-220 & TO-263 packages.
APPLICATIONS
Powering VGA & Sound Card
PowerPCTM Supplies
SMPS Post Regulator
High Efficiency "Green" Computer
Systems
High Efficiency Linear Power Supplies
Constant Current Regulators
Adjustable Power Supplies
Battery Charger
Figure 1. Adjustable Output Linear Regulator
SPX29302A
V
OUT
V
IN
GND
ADJ
1
2
3
4
5
R1
R2
6.8
F
+
+
10
F
DESCRIPTION
TYPICAL APPLICATION S CIRCUIT
Refer to page 7 for pinouts.
Now Available in Lead Free Packaging
Date: 5/25/04
SPX29302A 3Amp LDO Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
2
ABSOLUTE MAXIMUM RATINGS
Lead Temperature (soldering, 5 seconds) ................260
C
Storage Temperature Range........................-65
C to +150
C
Operating Junction Temperature Range......-40
C to +125
C
Input Voltage (Note 7) .................................................... 16V
(Note 1) at V
IN
=V
OUT
+ 1V and I
OUT
= 10mA, C
IN
= 6.8
F, C
OUT
= 10
F, T
j
= 25
C, unless otherwise specified. The Boldface
applies over the junction temperature range.
SPX29302A
PARAMETER
CONDITIONS
TYP
MIN
MAX
UNITS
Line Regulation
I
OUT
=10mA,(V
OUT
+1V)
V
IN
16V
0.06
0.5
%
Load Regulation
V
IN
=V
OUT
+5V, 10mA
I
OUT
I
FL
(Note 2)
0.2
1
%
V/T
V
OUT
Temp Coefficient (Note 6)
20
100
ppm/
C
Dropout Voltage, except
I
OUT
=100mA
50
175
mV
1.8V, (Note 3)
I
OUT
=1.5A
250
I
OUT
=3.0A
370
600
Ground Current
I
OUT
=1.5A, V
IN
=V
OUT
+1V
10
35
mA
(Note 5)
I
OUT
=3.0A
37
Ground Pin Current
V
IN
=0.5V less than specified V
OUT,
1.7
mA
at Dropout
I
OUT
=10mA
Current Limit
V
OUT
=0V (Note 4)
4.0
5.0
A
Output Noise Voltage
C
L
=10
F
400
V
RMS
(10Hz to 100kHz)
I
L
=100mA
C
L
=33
F
260
Reference Voltage
1.240
1.228
1.252
V
MAX
1.215
1.265
Reference Voltage
(Note 8)
1.203
1.277
V
Adjust Pin Bias Current
40
80
nA
120
Reference Voltage
(Note 7)
20
ppm/
C
Temp. Coeff.
Adjust Pin Bias
0.1
nA/
C
Current Temp. Coeff.
ENABLE Input
Input Logic Voltage
Low (OFF)
V
IN
<10V
0.8
V
High (ON)
2.4
ENABLE Input Pin
V
EN
=16V
100
600
A
750
V
EN
=0.8V
1
A
2
Regulator Output
(Note 10)
10
500
A
Current in Shutdown
Thermal Resistance
TO-220 Junction to Case, at Tab
2
C/W
TO-220 Junction to Ambient
60
TO-263 Junction to Case, at Tab
2
TO-263 Junction to Ambient
60
NOTES:
Note 1: Maximum positive supply voltage of 20V must be of limited duration (<100msecond) < 1% and duty cycle of less than 1%. The maximum continuous
supply voltage is 16V.
Note 2: Full load current (I
FL
) is defined as 3.0A.
Note 3: Dropout voltage is defined as the input to output differential when the output voltage drops to 99% of its nominal value.
Note 4: V
IN
= V
OUT
(NOMINAL)
+1V. For example, use V
IN
= 4.3V for a 3.3V regulator. Employ pulse-testing procedures to minimize temperature rise.
Note 5: Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current to the ground current.
Note 6: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range
Note 7: Thermal regulation is defined as the change in output voltage at time T after a change in power dissipation is applied, excluding load / line regulation effects.
Specifications for a 200mA load pulse as V
IN
= 16V (a 4W pulse) for t = 10ms.
Note 8: V
REF
V
OUT
(V
IN
-1), 2.3V
V
IN
16V, 10mA I
L
I
FL
, T
j
T
jmax
.
Note 9: Comparator threshold is expressed in terms of a voltage differential at the Adjust terminal below the nominal reference voltage measured 6V input. To
express these thresholds in terms of output voltage change, multiply the error amplifier gain = V
OUT
/V
REF
= (R1 + R2)/R2. For example, at a programmable
output voltage of 5V, the Error output is guaranteed to go low when the output drops by 95mVx 5V/ 1.240V = 38mV. Threshold remain constant as a percent of
V
OUT
as V
OUT
is varied, with the dropout warning occurring at typically 5% below nominal, 7.7% guaranteed.
Note 10: V
EN
0.8V and V
IN
16V, V
OUT
= 0.
ELECTRICAL CHARACTERISTICS
3
Date: 5/25/04
SPX29302A 3Amp LDO Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
Reference
Thermal
Shutdown
EN
IN
OUT
ADJ
GND
O.V
I
LIMIT
28V
R1*
R2*
1.180V
1.240V
+
+
-
-
FLAG
BLOCK DIAGRAM
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 2. Dropout Voltage vs Load Current
Figure 3. Line Regulation
Figure 4. Ground Current vs Load Current
Figure 5. Load Regulation
Figure 6. Enable Threshold vs Temperature
0
200
400
600
800
1000
0
1.0
2.0
3.0
IL (A)
V
OUT
=3.3V
CL = 10
F
Vdropout (mV)
1200
Vin = 3.2V
85
C
25
C
2.460
2.470
2.480
2.490
2.500
2.510
2.520
2.530
2.540
4
6
8
10
12
14
16
Vin (V)
V
OUT
=2.5V
IL = 10mA
CL = 10
F
V
out (V)
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
0
1.0
2.0
3.0
IL (A)
V
OUT
=3.3V
Vin = 4.3V
CL = 10
F
Ignd (mA)
85
C
25
C
3.280
3.285
3.290
3.295
3.300
3.305
3.310
0
1.0
2.0
3.0
IL (A)
V
IN
= 4.3V
CL = 10
F
V
OUT
=3.3V
V
out (V )
1.2
1.3
-40
-20
0
20
40
60
80
100
120
Temperature (
o
C)
V
OUT
=3.3V
Vth (V)
1.4
1.5
1.6
1.7
1.8
1.9
Date: 5/25/04
SPX29302A 3Amp LDO Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
4
The SPX29302A incorporates protection
against over-current faults, reversed load
insertion, over temperature operation, and
positive and negative transient voltage.
Thermal Considerations
Although the SPX29302A offers limiting
circuitry for overload conditions, it is still
necessary to insure that the maximum junction
temperature is not exceeded in the applica-
tion. Heat will flow through the lowest
resistance path, the junction-to-case path. In
order to insure the best thermal flow of the
component, proper mounting is required.
TO-220 Design Example:
Assume that V
IN
= 10V, V
OUT
= 5V, I
OUT
=
1.5A, T
A
= 50
C,
HA
= 1
C/W,
CH
= 2
C/W,
and
JC
= 3C
/W, where:
T
A
= ambient temperature,
HA
= heatsink to ambient thermal
resistance
CH
= case to heatsink thermal
resistance
JC
= junction to case thermal
resistance
The power calculated under these conditions
is:
P
D
= (V
IN
V
OUT
) * I
OUT
= 7.5W.
And the junction temperature is calculated as
T
J
= T
A
+ P
D
* (
HA
+
CH
+
JC
) or
T
J
= 50 + 7.5 * (1+2+3) = 95
C
Reliable operation is insured below 125
C.
Capacitor Requirements
The output capacitor is needed to insure
stability and minimize the output noise. The
value of the capacitor varies with the load.
However, a minimum value of 10
F alumi-
num capacitor will guarantee stability over all
load conditions. A tantalum capacitor is
recommended if a faster load transient
response is needed. If the power source has a
high AC impedance, a 0.1
F ceramic capaci-
tor between input & ground is recommended.
Minimum Load Current
To ensure a proper behavior of the regulator
under light load, a minimum load of 5mA for
SPX29302A is required.
Adjustable Regulator Design
The SPX29302A are adjustable regulators that
can be programmed to any value between
1.25V and 16V using 2 resistors, R1 and R2.
The relationship between the resistors is:
R1 = R2(V
OUT
/1.240-1).
Enable Input
The SPX29302A has an Enable function that
switches the regulator on and off.
Its thresholds is TTL compatible. When the
regulator is active, approximately 20 uA flows
through the Enable pin.
Typical Application Circuits
Figure 1 represents an adjustable output linear
regulator. The values of R1 and R2 set the
output voltage value as follows:
V
OUT
=V
REF
* [1 + (R1/R2)].
For best results, the total series resistance
should be small enough to pass a minimum
regulator load current of 5 mA. A minimum
value of 10kohms is recommended for R2
with a range between 10kohms and 47 kohms.
APPLICATION INFORMATION
5
Date: 5/25/04
SPX29302A 3Amp LDO Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
.160 - .190
0 - .010
Dimensions in (mm)
5 PIN TO-263
JEDEC TO-263
(BB) Variation
.020 - .039
.015 - .029
.070 - .110
-
- -
A
A1
b
c
E
E1
L
L1
L2
MIN NOM MAX
e
.067 BSC
.066
-
D1
.270 - -
.380 - .420
.245
-
-
H
.575 - .625
.070
L3
.010 BSC
c
WITH PLATING
BASE METAL
(b)
CONTACT AREA
1
2
3
4
5
E
E
L2
5X b
e
4X
(DATUM A)
c2
.045 - .023
c
C2
A
H
SEATING PLANE
D1
L1
(E)
E1
L
0-8
L3
5 PIN TO-263
PACKAGE: 5 PIN TO-263
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