Rev. 10/24/00
SPX2931
100mA Low Dropout Voltage Regulator
FEATURES
• 3.5V, 3.3V, and 3.0V Versions are Available
• Reverse Battery Protection
• Output Current in Excess of 100 mA
• Short Circuit Protection
• Input-Output Differential is Less Than 0.6V
• 60V Load Dump Protection
• Mirror-Image Insertion Protection
• -20V Reverse Transient Protection
• Internal Thermal Overload Protection
APPLICATION
• Available in TO-220, TO-92, SOT-89, and SO-8 Package Types
• Portable Instrumentation
• Available as Adjustable with TTL Compatible Switch
• Radio Control Systems
• Similar Improved to Industry Standard LM2931
• Cordless Telephones
PRODUCT DESCRIPTION
The SPX2931 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 SPX2931 features offers very low quiescent currents
(0.4 mA.), and very low drop output voltage (typ. 50 mV at light load and 300 mV at 100 mA). Other features include the logic-
compatible On/Off input which enables the regulator to be switched on and off. The SPX2931 is offered in a 3-pin TO-92/TO-220
package and SOT-89/SO-8 package.
PIN CONNECTIONS
Bottom View
TO-92 (N)
SPX2931
SOT-89 (M1)
Top View
1
2
3
V
IN
GND V
OUT
1
3
2
GND
V
IN
V
OUT
Top View
2
1
3
4
8
7
6
5
SPX2931
8-Pin Surface Mount (S)
Fixed Output
V
OUT
GND
GND
BYP
ON/OFF
GND
GND
V
IN
Front View
TO-220-3 (U)
Fixed
SPX2931
1
2
3
1. V
IN
2. GND
3. V
OUT
Rev. 10/24/00
SPX2931
ABSOLUTE MAXIMUM RATINGS
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 +85°C
Input Supply Voltage............................................. -0.3 to +26V
ESD Rating.........................................................................2KV
ELECTRICAL CHARACTERISTICS
at V
S
= 14V, T
A
= 25°C, I
O
= 10 mA, C2 = 100
µF, unless otherwise specified.
( Note 1)
Parameter Conditions
SPX2931A
SPX2931
Units
Min
Typ
Max
Min
Typ
Max
3.0 Volt Version
SPX2931A-3 SPX2931-3
Output Voltage
6V<V
IN
< 26V,
I
O
= 100 mA Over Temp.
2.94
2.88
3.00
3.00
3.06
3.12
2.91
2.85
3.00
3.00
3.09
3.15
V
V
3.3 Volt Version
SPX2931A-3.3 SPX2931-3.3
Output Voltage
6V < V
IN
< 26V,
I
O
= 100 mA Over Temp.
3.23
3.20
3.30
3.30
3.36
3.39
3.20
3.16
3.30
3.30
3.39
3.43
V
V
5 Volt Version
SPX2931A-5 SPX2931-5
Output Voltage
6V <V
IN
< 26V,
I
O
=100 mA Over Temp.
4.81
4.75
5.00 5.19
5.25
4.75
4.5
5.00 5.25
5.5
V
V
All Voltage Options
Long Term Stability
20
20
mV/1000
Line Regulation
9V < V
IN
< 16V
6V < V
IN
< 26V,
2.0
4.0
10
30
4.0
30 mV
Load Regulation
5 mA < I
O
< 100 mA
14
50
14
50
mV
Dropout Voltage
I
O
=10 mA
I
O
=50 mA
I
O
=100 mA
0.05
0.07
0.3
0.2
0.1
0.6
0.05
0.07
0.3
0.2
0.1
0.6
V
V
V
Quiescent Current
I
O
< 10 mA, 6V < V
IN
< 26V
-40
°C < Tj < 85°C
I
O
= 100 mA, V
IN
= 14V,
T
J
= 25
°C
0.4
15
1.0 0.4
15
1.0
mA
mA
Maximum Operational Input
Voltage
26 33 26 33
V
Maximum Line Transient
R
L
= 500
Ω, V
O
<5.5V, 100ms
60 70 50 70
V
Reverse Polarity Input
Voltage, DC
V
O
> -0.3V, R
L
= 500
Ω
-15 -30 -15 30
V
Reverse Polarity Input
Voltage, Transient
1% Duty Cycle,
τ < 100ms,
R
L
= 500
Ω
-50 -80 -50 -80
V
Output Noise Voltage
10Hz-100kHz, C
OUT
=100
µF
500
500 µVrms
Ripple Rejection
F
O
= 120Hz
80
80
dB
Note 1: See
TYPICAL APPLICATIONS
notes to ensure constant junction temperature, low duty cycle pulse testing used.
Note 2: All limits are at 25
°C or over the full operating temperature junction range of -40°C to +85°C.
Note 3: The maximum power dissipation is a function of maximum junction temperature, total thermal resistance, and ambient temperature.
Note 4: Human body model, 100
µF discharged through 1.5 KΩ.
Rev. 10/24/00
SPX2931
Application Hints
The SPX2931 requires an output capacitor for device stability.
The value required varies greatly depending upon the
application circuit and other factors. The high frequency
characteristics of electrolytic capacitors depend greatly on the
type and also on the manufacturer. Sometimes only bench
testing is the only means to determine the proper capacitor
type and value. The high quality 100
µF aluminum
electrolytic covers all general application circuits, this stability
can be obtained with a tantalum electrolytic value of 47
µF.
Another critical point of electrolytic characteristics is its
performance over temperature. The SPX2931 is designed to
operate starting at -40
°C which may not be true in the case of
electrolytic. Higher temperatures generally no problem. The
electrolytic. type in aluminum will freeze around -30
°C. This
could cause an oscillation at output of regulator. At a lower
temperature requirement by many applications the capacitor
should maintain its performance. So as a result, for an
application which regulator junction temperature does not
exceed 25
°C, the output capacitor can be reduced by the
factor of two over the value needed for the entire
temperature range.
Other points with linear regulators is that the twitch higher
output current stability decreases. In most applications the
SPX2931 is operating at few milliamps. In these
applications the output capacitance can be further reduced.
For example, when the regulator is running at 10mA output
current the output capacitance value is half compared to the
same regulator that is running at 100 mA.
With the SPX2931 adjustable regulator, the minimum value
of output capacitance is a function of the output voltage.
The value decreases with higher output voltages, since the
internal loop gain is reduced.
The worst case occurs at the lower temperature and
maximum operating currents, the entire circuit and the
electrolytic, should be cooled down to the minimum
temperature. The minimum of 0.6 volts required at the input
of regulator above the output to keep the power dissipation
and die heating to its minimum. After the value for the
capacitor has been determined for actual use, the value
should be doubled.
Rev. 10/24/00
SPX2931
TYPICAL CHARACTERISTICS
INPUT OUTPUT DIFFERENTIAL (V)
0.6
0.5
0.2
0
JUNCTION TEMPERATURE (ºC)
QUIESCENT CURRENT (mA)
25
3
2
0
-40
0
80
120
JUNCTION TEMPERATURE (ºC)
0.4
0.3
0.1
0
40
80
120
DROPOUT VOLTAGE
QUIESCENT CURRENT
6.0
3.0
2.0
1.0
2.0
3.0
4.0
5.0
6.0
INPUT VOLTAGE (V)
LOW VOLTAGE BEHAVIOR
OUTPUT VOLTAGE (V)
1.0
0.8
0.6
0.5
0
5
10
15
20
25
30
AMBIENT TEMPERATURE (ºC)
MAXIMUM POWER DISSIPATION (SO-
8)
POWER DISSIPATION (W)
0.9
0.7
0.4
10
1
0.1
0
30
60
90
120
150
FREQUENCY (Hz)
MAXIMUM POWER DISSIPATION
OUTPUT IMPEDANCE (
Ω)Ω)Ω)Ω)
0.01
INPUT OUTPUT DIFFERENTIAL (V)
0.4
0.2
OUTPUT CURRENT (mA)
QUIESCENT CURRENT (mA)
0
0
OUTPUT CURRENT (mA)
0.3
0.1
0
DROPOUT VOLTAGE
QUIESCENT CURRENT
22
20
6
0
0 10 20
40
70 80
100
AMBIENT TEMPERATURE (ºC)
MAXIMUM POWER DISSIPATION (TO-220)
POWER DISSIPATION (W)
REFERENCE VOLTAGE (V)
1.10
18
21
OUTPUT VOLTAGE (V)
REFERENCE VOLTAGE
OUTPUT CURRENT (mA)
800
500
0
INPUT VOLTAGE (V)
200
100
10
20
PEAK OUTPUT CURRENT
1.0
0
20
40 50 60
AMBIENT TEMPERATURE (ºC)
MAXIMUM POWER DISSIPATION (TO-92)
POWER DISSIPATION (W)
30
60
90
5
10
15
20
25
30
0
50
100
1.12
1.18
1.22
1.26
1.30
9
12
300
400
0.9
0.8
0.7
0.6
0.5
0.4
OPERATION DURING LOAD DUMP
TIME (ms)
OUTPUT
VOLTAGE (V)
400
200
100
-100
30
10
0
6
4
-2
10
15
20
15
30
18
2
0
0
300
1
~
~
~
~
40
I
O
= 0mA
I
O
= 50mA
V
IN
= 14V
24
6
3
0
1.14
1.16
1.24
1.20
1.28
LM2931CT ADJUSTABLE
I
O
= 100mA
I
O
= 50mA
I
O
= 10mA
0.5
0.6
0
T
J
= 25ºC
T
J
= 85ºC
T
J
= -40ºC
4.0
5.0
LM2931 5.0
I
O
= 100 mA
INFINITE HEAT SINK
10 ºC/W HEAT SINK
NO HEAT SINK
14
16
12
10
8
4
2
30
50 60
90
0.1
0.3
0.2
0
10
30
70 80 90
0.125" LEAD LENGTH
FROM PC BOARD
0.4" LENGTH
FROMPC BOARD
LM2931-
5.0
I
O
= 10mA
0.3
0.2
0.1
0
~
~
20
40
50
60
70
500
OUTPUT
VOLTAGE (V)
~
~
C
O
= 100µF
R
L
= 500W
Rev. 10/24/00
SPX2931
TYPICAL APPLICATIONS
SCHEMATIC DIAGRAM
AS2931
AS2931 Fixed Output
SPX2931
SPX2931 Fixed Output
Rev. 10/24/00
SPX2931
ORDERING INFORMATION
Ordering No.
Precision
Output Voltage
Packages
SPX2931N
3%
Adj
3 Lead TO-92
SPX2931N-3.0
3%
3.0V
3 Lead TO-92
SPX2931N-3.3
3%
3.3V
3 Lead TO-92
SPX2931N-3.5
3%
3.5V
3 Lead TO-92
SPX2931AN
2%
Adj
3 Lead TO-92
SPX2931AN-3.0
2%
3.0V
3 Lead TO-92
SPX2931AN-3.3
2%
3.3V
3 Lead TO-92
SPX2931AN-3.5
2%
3.5V
3 Lead TO-92
SPX2931CN
5%
Adj
3 Lead TO-92
SPX2931CN-3.0
5%
3.0V
3 Lead TO-92
SPX2931CN-3.3
5%
3.3V
3 Lead TO-92
SPX2931CN-3.5
5%
3.5V
3 Lead TO-92
SPX2931S
3%
Adj
8 Lead SOIC
SPX2931S-3.0
3%
3.0V
8 Lead SOIC
SPX2931S-3.3
3%
3.3V
8 Lead SOIC
SPX2931S-3.5
3%
3.5V
8 Lead SOIC
SPX2391AS
2%
Adj
8 Lead SOIC
SPX2391AS-3.0
2%
3.0V
8 Lead SOIC
SPX2391AS-3.3
2%
3.3V
8 Lead SOIC
SPX2391AS-3.5
2%
3.5V
8 Lead SOIC
SPX2931CS
5%
Adj
8 Lead SOIC
SPX2931CS-3.0
5%
3.0V
8 Lead SOIC
SPX2931CS-3.3
5%
3.3V
8 Lead SOIC
SPX2931CS-3.5
5%
3.5V
8 Lead SOIC
SPX2931U
3%
Adj
3 Lead TO-220
SPX2931U-3.0
3%
3.0V
3 Lead TO-220
SPX2931U-3.3
3%
3.3V
3 Lead TO-220
SPX2931U-3.5
3%
3.5V
3 Lead TO-220
SPX2931AU
2%
Adj
3 Lead TO-220
SPX2931AU-3.0
2%
3.0V
3 Lead TO-220
SPX2931AU-3.3
2%
3.3V
3 Lead TO-220
SPX2931AU-3.5
2%
3.5V
3 Lead TO-220
SPX2931CU
5%
Adj
3 Lead TO-220
SPX2931CU-3.0
5%
3.0V
3 Lead TO-220
SPX2931CU-3.3
5%
3.3V
3 Lead TO-220
SPX2931CU-3.5
5%
3.5V
3 Lead TO-220
SPX2931M1
3%
Adj
3 Lead SOT-89
SPX2931M1-3.0
3%
3.0V
3 Lead SOT-89
SPX2931M1-3.3
3%
3.3V
3 Lead SOT-89
SPX2931M1-3.5
3%
3.5V
3 Lead SOT-89
SPX2931AM1
2%
Adj
3 Lead SOT-89
SPX2931AM1-3.0
2%
3.0V
3 Lead SOT-89
SPX2931AM1-3.3
2%
3.3V
3 Lead SOT-89
SPX2931AM1-3.5
2%
3.5V
3 Lead SOT-89
SPX2931CM1
5%
Adj
3 Lead SOT-89
SPX2931CM1-3.0
5%
3.0V
3 Lead SOT-89
SPX2931CM1-3.3
5%
3.3V
3 Lead SOT-89
SPX2931CM1-3.5
5%
3.5V
3 Lead SOT-89
Rev. 10/24/00
SPX2931
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