1
Date: 08/25/04
SPX2941 1A Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
1A Low Dropout Voltage Regulator,
Adjustable Output, Fast Response
SPX2941
DESCRIPTION
FEATURES
Adjustable Output Down To 1.25V
Low Quiescent Current
Guaranteed 1.5A Peak Output Current
Low Dropout Voltage of 280mV @ 1A
Extremely Tight Load and Line
Regulation
Extremely Fast Transient Response
Reverse-battery Protection
Internal Thermal and Current Limit
Protection
Zero Current Shutdown
Error Flag Output for Out of Regulation
State
Standard TO-220 and TO-263
packages
Replacement for LM2941 and AS2941
Figure 1. Adjustable Output Linear Regulator
The SPX2941 is a 1A, accurate voltage regulator with a low drop out voltage of 280mV(typ.) at
1A. These regulators are specifically designed for low voltage applications that require a low
dropout voltage and a fast transient response. They are fully fault protected against over-current,
reverse battery, and positive and negative voltage transients. Other features include Enable, and
Error Flag. The SPX2941 is offered in 5-pin TO-220 & TO-263 packages. For a 3A version, refer
to the SPX29300 data sheet.
SPX2941
V
OUT
V
IN
GND
ADJ
4
2
3
5
1
R1
R2
10F
6.8F
+
+
EN
TYPICAL APPLICATIONS CIRCUIT
Now Available in Lead Free Packaging
1 2 3 4 5
SPX2941
5 Pin TO-263
V
IN
GND
V
OUT
ADJUST
ENABLE
APPLICATIONS
Powering VGA & Sound Card
LCD Monitors
USB Power Supply
Power PC Supplies
SMPS Post-Regulator
High Efficiency Linear Power Supplies
Battery Charger
Portable Instrumentation
Constant Current Regulators
Adjustable Power Supplies
Date: 08/25/04
SPX2941 1A Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
2
ABSOLUTE MAXIMUM RATINGS
Lead Temperature (soldering, 5 seconds) ................260C
Storage Temperature Range........................-65C to +150C
PARAMETER
CONDITIONS
MIN.
TYP.
MAX
UNIT
Reference Voltage
Adjustable version only
1.228
1.240
1.252
V
1.215
1.265
Adjust Pin Bias Current
40
80
V
120
Reference Voltage
(N
OTE
4)
20
ppm/C
Temperature Coefficient
Adjust Pin Bias Current
0.1
nA/C
Temperature Coefficient
Line Regulation
I
OUT
=10mA, (V
OUT
+1V)V
IN
16V
0.2
1.0
%
Load Regulation
V
IN
=V
OUT
+1V, 10mAI
OUT
I
FULL
0.3
1.5
%
Dropout Voltage (Note1)
I
OUT
=100mA
70
200
mV
(except 1.8V version)
I
OUT
=1A
280
550
Ground Current (Note3)
I
OUT
=750mA, V
IN
=V
OUT
+1V
12
25
mA
I
OUT
=1A
18
Ground Pin Current at
V
IN
=0.1V less than specified V
OUT
,
1.2
mA
Dropout
I
OUT
=10mA
Current Limit
V
OUT
=0V (Note2)
1.5
2.2
A
Output Noise Voltage
10Hz to 100kHz, I
OUT
=100mA,
C
L
=10F
400
V
RMS
C
L
=33F
260
ERROR COMPARATOR (FLAG OUTPUT)
Output Leakage Current
V
OH
=16V
0.1
1
A
2
Output Low Voltage
Device set for 5V,
200
300
mV
V
IN
=4.5, I
OL
=250A
400
Upper Threshold Voltage
Device set for 5V (Note 5)
40
60
mV
25
Lower Threshold Voltage
Device set for 5V (Note 5)
75
95
mV
140
Hysteresis
Device set for 5V (Note 5)
15
mV
Input Logic Voltage
LOW (OFF)
V
IN
<10V
0.8
V
HIGH (ON)
2.4
ENABLE Input Pin Current
V
EN
=16V
100
600
A
750
V
EN
=0.8V
1
A
2
Regulator Output Current
(N
OTE
6)
10
A
in Shutdown
500
Thermal Resistance
TO-220
Junction to Case, at Tab
3
C/W
Junction to Ambient
60
TO-263
Junction to Case, at Tab
3
C/W
Junction to Ambient
60
V
IN
=V
OUT
+ 1V, I
OUT
=10mA, C
IN
=6.8
F, C
OUT
=10
F, T
A
= 25
C, unless otherwis specified. The boldface applies over the
junction temperature range. Adjustable versions are set at +5.0V.
Operating Junction Temperature Range......-40C to +125C
Input Supply Voltage (N
OTE
7) .... .....................................16V
ELECTRICAL CHARACTERISTICS
3
Date: 08/25/04
SPX2941 1A Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
N
OTE
1: Dropout voltage is defined as the input to output differential at which the output voltage drops to 99%
of its nominal value.
N
OTE
2: V
IN
=V
OUT(NOMINAL)
+1V; for example, V
IN
=4.3V for a 3.3V regulator. Employ pulse-testing procedures to
minimize temperature rise.
N
OTE
3: Ground pin current is the regulator quiescent current. The total current drawn from the source is the
sum of the load and ground currents.
N
OTE
4: Thermal regulation is defined as the change in the output voltage at a time T after a change in power
dissipation is applied, excluding load or line regulation effects.
N
OTE
5: 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
= (R
1
+ R
2
)/R
2
. 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.
N
OTE
6: V
EN
0.8V and V
IN
16V, V
OUT
= 0.
N
OTE
7: Maximum positive supply voltage of 20V must be of limited duration ( <100ms) and duty cycle (<1%).
The maximum continuous supply voltage is 16V.
N
OTE
8: V
REF
V
OUT
(V
IN
-1), 2.5V V
IN
16V, 10 mA I
C
I
FL
, T
J
< T
JMAX
.
Reference
Thermal
Shutdown
EN
IN
OUT
ADJ
GND
O.V
I
LIMIT
28V
R1*
R2*
1.180V
1.240V +
+
-
-
FLAG
Figure 2. SP2941 Block Diagram
BLOCK DIAGRAM
Date: 08/25/04
SPX2941 1A Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
4
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 3. Line Regulation for 3.3V Device
Figure 4. Load Regulation for 3.3V Device
Figure 7. Ground Current vs Load Current in Dropout
Figure 8. Dropout Voltage vs Load Current for 3.3V
Device
Figure 5. Ground Current vs Load Current for 3.3V Device Figure 6. Ground Current vs Input Current
3.320
3.315
3.310
3.305
3.300
3.295
3.290
3.285
3.280
4
6
8
10
12
14
16
V
IN
(V)
V
OUT
(V)
3.3V Device
IL = 10mA
CL = 10F
3.310
3.305
3.300
3.295
3.290
3.285
3.280
IL (A)
V
OUT
(V)
0.00
0.25
0.50
0.75
1.00
1.25
1.50
3.3V Device
V
IN
= 4.3V
CL = 10F
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
IL (A)
IGnd (mA)
0.00
0.25
0.50
0.75
1.00
1.25
1.50
3.3V Device
V
IN
= 4.3V
CL = 10F
300
280
260
240
220
200
180
4
6
8
10
12
14
16
V
IN
(V)
IGnd (
A)
3.3V Device
IL = 10mA
CL = 10F
100
90
80
70
60
50
40
30
20
10
0
IL (A)
IGnd (mA)
0.00
0.25
0.50
0.75
1.00
1.25
1.50
3.3V Device
V
IN
= 3.2V
CL = 10F
600
500
400
300
200
100
0
IL (A)
V
DR
OPOUT
(mV)
0.00
0.25
0.50
0.75
1.00
1.25
1.50
3.3V Device
CL = 10F
5
Date: 08/25/04
SPX2941 1A Low Dropout Voltage Regulator
Copyright 2004 Sipex Corporation
Figure 9. Ground Current vs Temperature at I
LOAD
=10mA
Figure 10. Output Voltage vs Temperature at I
LOAD
=10mA
Figure 11. Ground Current vs Temperature at I
LOAD
=500mA Figure 12. Ground Current vs Temperature in Dropout
at I
LOAD
=750mA
Figure 13. Ground Current vs Temperature at I
LOAD
=1.5A
Figure 14. Ground Current vs Temperature in Dropout at
I
LOAD
=1.5A
280
270
260
250
240
230
220
210
200
190
180
-40
-20
0
20
40
60
80
Temperature (C)
IGnd (
A)
3.3V Device
V
IN
= 4.3V
IL = 10mA
CL = 10F
120
100
3.320
3.310
3.300
3.290
3.280
3.270
3.260
3.250
3.240
3.230
3.220
-40
-20
0
20
40
60
80
Temperature (C)
V
OUT
(V)
3.3V Device
V
IN
= 4.3V
IL = 10mA
CL = 10F
120
100
7.00
6.80
6.60
6.40
6.20
6.00
5.80
5.60
5.40
5.20
5.00
-40
-20
0
20
40
60
80
Temperature (C)
IGnd (mA)
3.3V Device
V
IN
= 4.3V
IL = 500mA
CL = 10F
120
100
30
29
28
27
26
25
24
23
22
21
20
-40
-20
0
20
40
60
80
Temperature (C)
IGnd (mA)
3.3V Device
V
IN
= 3.2V
IL = 750mA
CL = 10F
120
100
52.0
50.0
48.0
46.0
44.0
42.0
40.0
38.0
36.0
-40
-20
0
20
40
60
80
Temperature (C)
IGnd (mA)
3.3V Device
V
IN
= 4.3V
IL = 1.5A
CL = 10F
120
100
100
95
90
85
80
75
70
-40
-20
0
20
40
60
80
Temperature (C)
IGnd (mA)
3.3V Device
V
IN
= 3.2V
IL = 1.5A
CL = 10F
120
100
TYPICAL PERFORMANCE CHARACTERISTICS
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