Rev. 10/23/00
SPX2840
4A Low Dropout Voltage Regulator
Adjustable & Fixed 3.3V
FEATURES
APPLICATIONS
Adjustable Output Down To 1.25V Or Fixed 3.3V Powering Intel Pentium P from +5V Supplies
Output Current Of 4A
Power PC Supplies
Low Dropout Voltage
SMPS Post-Regulator
Extremely Tight Load And Line Regulation
High Efficiency "Green" Computer Systems
Current & Thermal Limiting
High Efficiency Linear Power Supplies
Standard 3-Terminal Low Cost TO-220
Portable Instrumentation
Constant Current Regulators
Adjustable Power Supplies
Battery Charger
PRODUCT DESCRIPTION
The SPX2840 is a low power 4A Adjustable Voltage Regulator that is very easy to use. It requires only 2 external resistors to set the
output voltage. This device is an excellent choice for use in Powering Intel
Microprocessor to convert from +5V to 3.3V supplies
and as a post regulator for switching supplies applications. The SPX2840 features low dropout of a maximum 1.3 volts.
The SPX2840 offers over-current limit and full protection against reversed input polarity, reversed load insertion, over temperature
operation, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The I
Q
of this device
flows in to the load, which increases the efficiency.
The SPX2840 is offered in a 3-pin TO-220 package compatible with other 3 terminal regulators. For a 3A low dropout regulator refer
to the SPX2830 data sheet.
ORDERING INFORMATION
Front View
TO-220-3 (U)
SPX2840
1
2
3
ADJ/GND V
OUT
V
IN
Rev. 10/23/00
SPX2840
ABSOLUTE MAXIMUM RATINGS
Power Dissipation..........................................Internally Limited
Input Supply Voltage .................................................... +10V
Lead Temp. (Soldering, 10 Seconds) .............................. 300C
Input to Output Voltage Differential ............................. +10V
Storage Temperature Range ............................ -65 to +150C
Operating Junction Temperature Range
SPX2840 Control Section..........................0C to +125C
SPX2840 Power Transistor........................0C to +150C
ELECTRICAL CHARACTERISTICS
.(NOTE 1) at I
OUT
= 10mA, T
A
=25
C, unless otherwise specified.
Parameter
Conditions SPX2840
Min Typ Max
Units
Reference Voltage
10 mA
I
OUT
I
FULLLOAD
1.5V
(V
IN
- V
OUT
7V ( Over Temperature)
1.238
1.225
1.250
1.250
1.262
1.270
V
V
Min. Load Current
(V
IN
-V
OUT
) + 25V
5 10 mA
Line Regulation
1.5V
V
IN
- V
OUT
7V
I
LOAD
= 10mA
15V
V
IN
- V
OUT
7V
0.015
0.035
0.05
0.2
0.2
0.5
%
%
%
Load Regulation
10 mA
I
OUT
I
FULLLOAD
(V
IN
- V
OUT
)=3V
0.1
0.2
0.3
0.4
%
%
Dropout Voltage
I
OUT
=I
FULLLOAD
,
V
REF
=1%
1.1 1.3 V
Current Limit
V
IN
- V
OUT
=5V
V
IN
- V
OUT
=25V
5.5
0.3
6.5
0.6
A
A
Long Term Stability
T
A
=125
C, 1000 Hrs.
0.3 1 %
Adjust Pin Current
T
A
=25
C
55
120
A
A
Adjust Pin Current Change
0.2 5
A
Thermal Regulation
30 ms pulse
0.003
0.015
%/W
Temperature Stability
0.5
%
Ripple Rejection Ratio
V
IN
- V
OUT
=3V
I
OUT
=3A, C
OUT
= 25
F, C
ADJ
= 25
F, f= 120Hz
60 75 dB
Output Noise, RMS
10Hz to 10kHz
0.003 %
V
O
The Bold specifications apply to the full operating temperature range.
Note 1: Changes in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 2: A 10
F output capacitor is required on SPX2840.
Rev. 10/23/00
SPX2840
TYPICAL CHARACTERISTICS
Rev. 10/23/00
SPX2840
TYPICAL APPLICATIONS
Pentium Processor is a trademark of Intel Corp. Power PC is a trademark of Motorola Corp
.
IN
OUT
ADJ
SPX2840
C
1
R
1
V
OUT
Typical Adjustable Regulator
V
IN
LOAD
ADJ
SPX2840
4A Current output Regulator
V
IN
C
1
OUT
IN
R
2
C
2
V
OUT
= V
REF
(1 + R
2
) + I
ADJ
R
2
R
1
R
1
V
REF
IN
OUT
ADJ
+5V
3.45V
SPX2840
C
1
R
1
R
1
Powering Intel Pentium
TM
with SPX2840
V
IN
I
n
t
e
l
486
TM
C
2
V
CC
Rev. 10/23/00
SPX2840
ORDERING INFORMATION
Ordering No.
Precision
Output Voltage
Packages
SPX2840AU
2%
Adj
3 Lead TO-220
SPX2840AU-3.3
2%
3.3V
3 Lead TO-220
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and Main Offices:
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 935-7600
FAX: (408) 934-7500
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
hereing; neither does it convey any license under its patent rights nor the rights of others.
Corporation
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