Page 1
SPX2941
1A Low Dropout Voltage Regulators
(ADVANCED INFORMATION)
FEATURES APPLICATIONS
•Output Current 1A
• Internal Short Circuit Current Limit • Cordless Telephones
• Dropout Voltage 0.5V at 1A Output • Automotive Electronics
• Extremely Tight Load and Line Regulation • Portable / Palm Top / Notebook Computers
• Very Low Temperature Coefficient • Portable Consumer Equipment
• Mirror Image Insertion Protection • Portable Instrumentation
• Unregulated DC Input Can Withstand -20V Reverse Battery • SMPS Post-Regulator
and +60V Positive Transients
• Direct Replacement For LM2941 Socket
• Adjustable Output Between 5V to 20V
• TTL, CMOS Compatible ON/OFF Switch
• Battery Powered Systems
• Voltage Reference
PRODUCT DESCRIPTION
The SPX2941 is a low power positive Adjustable Voltage Regulator. The SPX2941 offers 1A output current with dropout voltage of
only 0.5 Volts with a maximum of 1V dropout over temperature. The quiescent current is 30mA at differential output of 5V and
output current of 1A. The higher quiescent current exists only when the device is in dropout mode
(V
– V
IN
Other key features of this device include higher output current, positive transient protection up to 60V (Load dump), and ability to
survive an unregulated input voltage transient of -20V below ground (reverse battery). The regulator will automatically shut down to
protect both the internal circuits and the load. This device also features short circuit and thermal overload protection.
The SPX2941 is offered in a 5-pin TO-263 and TO-220 package compatible with other adjustable regulators. This device offers an
adjustable output voltage from 5V to 20V. SPX2941 is a direct replacement to LM2941.
OUT
< 3V).
ADVANCED
TO-263-5 Package
PIN CONNECTIONS
SPX2941
12345
Top View
TO-220-5 Package
SPX2941
54321
Top View
2)
3)
4)
5)
ADJ1)
Shutdown
GND
V
IN
V
OUT
Rev. 10/24/00
Page 2
SPX2941
ABSOLUTE MAXIMUM RATINGS
Power Dissipation ..................................... Internally Limited Operating Input Supply Voltage ...................................+12V
Lead Temp. (Soldering, 10 seconds)........................... 260°C
Storage Temperature Range ....................... -65°C to +150°C
Operating Junction Temperature Range ................... +150°C
ESD Rating is to be determined
Feedback Input Voltage ................................. -1.5V to +30V
Shutdown Input Voltage ...................................-0.3V to 30V
Error Comparator Output .................................... -0.3 to 30V
ELECTRICAL CHARACTERISTICS
Boldface limits are over the entire operating temperature range.
SPX2941
Parameter Conditions Min Typ Max Units
Output Voltage 5mA < IO < 1A
Line Regulation
Load Regulation 50mA < IO < 1A
Dropout Voltage IL = 100mA
Output Impedance 100mADC, 20mArms,
Quiescent Current VO + 2V < VIN < 26V
RMS Output Noise % Voltage Out 10Hz - 100kHz
Ripple Rejection fO = 120Hz, 1 V
Long Term Stability 0.4 %/1000Hr
ON/OFF Threshold ON IO < 1A 1.3
ON/OFF Threshold OFF IO < 1A
ON/OFF Threshold Current IO < 1A
Short Circuit Current 1.6 1.9 A
Maximum Line Transient
Reverse Polarity DC Input Voltage
Reverse Polarity Transient Input Voltage
Maximum Operating Input Voltage 31 26 V
at
VIN = VO + 5V, IO = 1A, CO = 22 µF, 5V < VO < 20V, unless otherwise specified.
All other specifications apply are T
+ 2V < VIN < 26V
V
O
I
= 5mA
O-
I
= 1A
L
= 25°C.
A
1.237
1.211
1.275
4
7
110
0.5
1.313
1.339
10
10
10
10
200/
0.8
200
/1.0
7
f
= 120Hz
O
I
= 5mA
O
V
= VO + 5V
IN
I
= 5mA
O
10
30
15
20
45
60
0.003 %
I
= 5mA
O
I
= 100mA
O
V
ON/OFF
R
= 100Ω
O
100mS
T <
R
= 100Ω
O
R
= 100Ω
O
100mS
T <
= 2.0V
rms
0.005 0.02
0.04
0.80/
2.00
2.00/
50
60
60
-15
-15
-50
-50
1.3 V
100/
75 V
-30
-30
-75 V
0.80
300
V
V
V
mV
mV
mV
V
mΩ
mA
mA
%V
V
V
Rev. 10/24/00
Page 3
SPX2941
ELECTRICAL CHARACTERISTICS
0.9
TJ = 25 °C
0.8
0.7
0.6
0.5
0.4
0.3
INPUT-OUTPUT DIFFERENTIAL (V)
0.2
0.1
0
0 200 400 600 800 1000
Dropout Voltage
OUTPUT CURRENT (mA)
5.10
5.08
5.06
5.04
5.02
5.00
4.98
OUTPUT VOLTAGE (5V)
4.96
4.94
4.92
4.90
-40 0 40 80 120 160
Output Voltage vs. Temperature
TEMPERATURE (°C)
200
180
160
140
120
100
80
QUIESCENT CURRENT (mA)
60
40
20
0
0 5 10 15 20 25
Quiescent Current
100 mA
1 A
VIN = VO + 5V, IO =1A, CO = 22 µF, unless otherwise specified.
Dropout Voltage
1 A
500 mA
100 mA
TEMPERATURE (°C)
Quiescent Current vs. Temperature
VIN = VO +5V
1 A
TEMPERATURE (°C)
Quiescent Current
V
= 14V
IN
V
= 5V
O
= 25 °C
T
J
500 mA
500 mA
30 35
1.0
0.9
0.8
0.7
0.6
0.5
0.4
DROPOUT VOLTAGE (V)
0.3
0.2
0.1
0
-40 0 40 80 120 160
50
40
30
20
QUIESCENT CURRENT (mA)
10
0
-40 0 40 80 120 160
50
40
30
20
QUIESCENT CURRENT (mA)
10
0
0 0.2 0.4 0.6 0.8 1.0
10 mA
Rev. 10/24/00
Page 4
SPX2941
ELECTRICAL CHARACTERISTICS
30
20
10
0
-10
-20
OUTPUT VOLTAGE DEVIATION (mV)
-30
~
~
3V
Quiescent Current
INPUT VOLTAGE CHANGE (V)
0V
-100 10203040
95
VIN = 10V
= 22 µF
C
OUT
= 10 mA
T
J
85
V
= 5V
O
75
65
µµµµ
TIME (
s)
Ripple Rejection
55
RIPPLE REJECTION (dB)
45
35
1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
Maximum Power Dissipation (TO-220)
22
20
18
16
14
12
10
8
POWER DISSIPATION (W)
6
4
2
0 0
INFINITE HEAT SINK
10 °C/W HEAT SINK
NO HEAT SINK
AMBIENT TEMPERATURE ( °C)
VIN = VO + 5V, IO =1A, CO = 22 µF, unless otherwise specified.
Load Transient Response
VIN = 10V
= 22 µF
C
OUT
= 25 °C
T
J
= 5V
V
O
TIME (
s)
µµµµ
Output Impedance
FREQUENCY (Hz)
Maximum Power Dissipation (TO-263) (See Note 3)
= 32 °C/W
4
Θ
JA
3
= 37 °C/W
Θ
JA
2
POWER DISSIPATION (W)
1
0
0 102030405060708090100
AMBIENT TEMPERATURE ( °C)
~
~
50 60
Maximum Power Dissipation (TO-3)
22
INFINITE HEAT SINK
20
18
16
14
12
10
8
POWER DISSIPATION (W)
6
4
2
0 1020304050607080901000102030 6050 8070 9040 100
0.5
0.4
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
~
1.0
~
LOAD CURRENT (A) OUTPUT VOLTAGE DEVIATION (V)
0.5
0
-100 10203040
10.00
VIN = 10V
C
T
5.00
J
V
O
2.00
)
1.00
Ω
ΩΩ
Ω
0.50
0.20
0.10
OUTPUT IMPEDANCE (
0.05
0.02
0.01
1 10 100 1k 10k 100k 1M
10 °C/W HEAT SINK
NO HEAT SINK
AMBIENT TEMPERATURE ( °C/W)
= 22 µF
OUT
= 50 mA
= 5V
Θ
JA
~
~
= 50 °C/W
Θ
JA
= 73 °C/W
Rev. 10/24/00
Page 5
SPX2941
ELECTRICAL CHARACTERISTICS
5.0
I
= 1A
O
= 25 °C
T
J
V
O
4.0
3.0
Low Voltage Behavior
= 5V
OUTPUT VOLTAGE (V)
2.0
1.0
18
I
= 1A
O
= 25 °C
T
J
V
= 10V
O
15
12
9
6
OUTPUT VOLTAGE (V)
3
0
Output at Voltage Extremes
12
Ω
= 100
R
L
10
VO = 5V
8
6
4
2
OUTPUT VOLTAGE (V)
0
-2
Output at Voltage Extremes
25
Ω
= 100
R
L
20
VO = 10V
15
10
5
0
OUTPUT VOLTAGE (V)
-5
)
Ω
ΩΩ
Ω
INPUT VOLTAGE (V)
Low Voltage Behavior
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
100
10
12918630
15
20100-10-20-30
30 40
30 40
20100-10-20-30
Output Capacitor ESR
C
= 22 µF
OUT
= 5V
V
O
1
0.1
EQUIVALENT SERIES RESISTANCE (
0.01
OUTPUT CURRENT (mA)
STABLE
REGION
VIN = VO + 5V, IO =1A, CO = 22 µF, unless otherwise specified.
Low Voltage Behavior
14
I
= 1A
O
= 25 °C
T
J
12
= 8V
V
O
10
8
6
4
OUTPUT VOLTAGE (V)
2
0
6.05.04.03.02.01.0
14
12
10
OUTPUT VOLTAGE (V)
20
16
12
OUTPUT VOLTAGE (V)
-4
20
16
12
OUTPUT VOLTAGE (V)
-4
10008006004000 200
INPUT VOLTAGE (V)
Low Voltage Behavior
= 1A
I
O
= 25 °C
T
J
V
= 12V
O
8
6
4
2
0
INPUT VOLTAGE (V)
Output at Voltage Extremes
Ω
= 100
R
L
VO = 8V
8
4
0
INPUT VOLTAGE (V)
Output at Voltage Extremes
Ω
R
= 100
L
VO = 12V
8
4
0
INPUT VOLTAGE (V)
OUTPUT CURRENT (A)
3.0
2.0
1.0
0
-40 0 40 80 120 160
1086420
12 14
1086420
12 14
20100-10-20-30
30 40
20100-10-20-30
30 40
18
15
12
9
6
OUTPUT VOLTAGE (V)
3
0
18
15
12
9
6
OUTPUT VOLTAGE (V)
3
0
20
16
12
8
4
0
OUTPUT VOLTAGE (V)
-4
25
20
15
10
5
0
OUTPUT VOLTAGE (V)
-5
Peak Output Current
TEMPERATURE ( °C)
Low Voltage Behavior
I
= 1A
O
= 25 °C
T
J
= 9V
V
O
INPUT VOLTAGE (V)
Low Voltage Behavior
I
= 1A
O
= 25 °C
T
J
V
= 15V
O
INPUT VOLTAGE (V)
Output at Voltage Extremes
Ω
= 100
R
L
VO = 9V
INPUT VOLTAGE (V)
Output at Voltage Extremes
Ω
R
= 100
L
VO = 15V
INPUT VOLTAGE (V)
V
= 14V
IN
12918630
15
12918630
15
20100-10-20-30
30 40
20100-10-20-30
30 40
Rev. 10/24/00
Page 6
SPX2941
APPLICATION HINTS
External Capacitors
A minimum capacitance of 22µF and conditions on ESR (Equivalent
Series Resistance) must be met. The minimum value for the
capacitance is 22µF and can be increased without limit. However the
ESR may cause loop instability if it is too high or too low. The
following graph shows the acceptable range for the ESR.
100
)
Ω
ΩΩ
Ω
10
1
0.1
EQUIVALENT SERIES RESISTANCE (
0.01
If the capacitor does not meet these requirements oscillation can
result.
ESR is specified only at room temperature. Therefore the designer
must ensure the proper behavior of the ESR over the temperature
range. ESR, for electrolytic capacitor, will increase by about 30X as
the temperature is reduced from 25°C to -40°C. Aluminum
electrolytic capacitors are not well suited for low temperature
operation.
Solid tantalum capacitors’ ESR are more stable over temperature, but
expensive. A cost-effective approach is then to put in parallel solid
tantalum and aluminum electrolytic capacitors in the ratio25/75%.
Thermal Consideration
Although the SPX2941 offers some limiting circuitry for overload
conditions, it is necessary not to exceed the maximum junction
temperature, and therefore to be careful about thermal resistance.
The heat flow will follow the lowest resistance path, which is the
Junction-to-case thermal resistance. In order to insure the best
thermal flow of the component, a proper mounting is required. Note
that the case of the device is electrically connected to the output. In
case the case has to be electrically isolated, a thermally conductive
spacer can be used. However do not forget to consider its
contribution to thermal resistance.
Output Capacitor ESR
STABLE
REGION
OUTPUT CURRENT (mA)
C
= 22 µF
OUT
= 5V
V
O
10008006004000 200
Rev. 10/24/00
Page 7
SPX2941
ORDERING INFORMATION
Ordering No. Output Voltage Packages
SPX2941T5
SPX2941U5
Adj 5 Lead TO-263
Adj 5 Lead TO-220
SIGNAL PROCESSING EXCELLENCE
Corporation
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 circui t described
hereing; neither does it convey any license under its patent rights nor the rights of others.
Rev. 10/24/00
Loading...