NSC LM2937IMP-5.0, LM2937IMP-15, LM2937IMP-12, LM2937IMP-10, LM2937ET-8.0 Datasheet
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LM2937
500 mA Low Dropout Regulator
General Description
The LM2937 is a positive voltage regulator capable of supplying up to 500 mAofloadcurrent.TheuseofaPNPpower
transistor provides a low dropout voltage characteristic. With
a load current of 500 mAthe minimum input to output voltage
differential required for the output to remain in regulation is
typically 0.5V (1V guaranteed maximum over the full operating temperature range). Special circuitry has been incorporated to minimize the quiescent current to typically only
10 mA with a full 500 mA load current when the input to output voltage differential is greater than 3V.
The LM2937 requires an output bypass capacitor for stability.As with most low dropout regulators, the ESR of this capacitor remains a critical design parameter, but the LM2937
includes special compensation circuitry that relaxes ESR requirements. The LM2937 is stable for all ESR below 3Ω. This
allows the use of low ESR chip capacitors.
Ideally suited for automotive applications, the LM2937 will
protect itself and any load circuitry from reverse battery con-
nections, two-battery jumps and up to +60V/−50V load dump
transients. Familiar regulator features such as short circuit
and thermal shutdown protection are also built in.
Features
n Fully specified for operation over −40˚C to +125˚C
n Output current in excess of 500 mA
n Output trimmed for 5% tolerance under all operating
conditions
n Typical dropout voltage of 0.5V at full rated load current
n Wide output capacitor ESR range, up to 3Ω
n Internal short circuit and thermal overload protection
n Reverse battery protection
n 60V input transient protection
n Mirror image insertion protection
Connection Diagram and Ordering Information
TO-220 Plastic Package
DS011280-2
Front View
Order Number LM2937ET-5.0, LM2937ET-8.0,
LM2937ET-10, LM2937ET-12 or LM2937ET-15
See NS Package Number T03B
SOT-223 Plastic Package
DS011280-26
Front View
Order Number LM2937IMP-5.0,
LM2937IMP-8.0, LM2937IMP-10,
LM2937IMP-12 or LM2937IMP-15
See NS Package Number MP04A
TO-263 Surface-Mount Package
DS011280-5
Top View
DS011280-6
Side View
Order Number LM2937ES-5.0, LM2937ES-8.0,
LM2937ES-10, LM2937ES-12 or LM2937ES-15
See NS Package Number TS3B
March 2000
LM2937 500 mA Low Dropout Regulator
© 2000 National Semiconductor Corporation DS011280 www.national.com
Connection Diagram and Ordering Information (Continued)
Temperature
Range
Output Voltage NSC Package
5.0 8.0 10 12 15 Package
Drawing
−40˚C ≤ T
J
≤ 125˚C LM2937ES-5.0 LM2937ES-8.0 LM2937ES-10 LM2937ES-12 LM2937ES-15 TS3B TO-263
LM2937ET-5.0 LM2937ET-8.0 LM2937ET-10 LM2937ET-12 LM2937ET-15 T03B TO-220
−40˚C ≤ T
J
≤ 85˚C LM2937IMP-5.0 LM2937IMP-8.0 LM2937IMP-10 LM2937IMP-12 LM2937IMP-15 MP04A SOT-223
LM2937IMPX-5.0 LM2937IMPX-8.0 LM2937IMPX-10 LM2937IMPX-12 LM2937IMPX-15 MP04A SOT-223
in Tape
and Reel
SOT-223 Package
Markings
L71B L72B L73B L74B L75B
The small physical size of the SOT-223 package does not allow sufficient space to provide the complete device part number. The actual devices will be labeled with
the package markings shown.
LM2937
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Input Voltage
Continuous 26V
Transient (t ≤ 100 ms) 60V
Internal Power Dissipation (Note 2) Internally Limited
Maximum Junction Temperature 150˚C
Storage Temperature Range −65˚C to +150˚C
TO-220 (10 seconds) 260˚C
TO-263 (10 seconds) 230˚C
SOT-223 (Vapor Phase, 60 seconds) 215˚C
SOT-223 (Infared, 15 seconds) 220˚C
ESD Susceptibility (Note 3) 2 kV
Operating Conditions (Note 1)
Temperature Range (Note 2)
LM2937ET, LM2937ES −40˚C ≤ T
J
≤125˚C
LM2937IMP −40˚C ≤ T
J
≤85˚C
Maximum Input Voltage 26V
Electrical Characteristics
VIN=V
NOM
+ 5V, (Note 4) I
OUTmax
= 500 mA for the TO-220 and TO-263 packages, I
OUTmax
=400mA for the SOT-223 pack-
age, C
OUT
= 10 µF unless otherwise indicated. Boldface limits apply over the entire operating temperature range of the
indicated device., all other specifications are for T
A=TJ
= 25˚C.
Output Voltage (V
OUT
) 5V 8V 10V Units
Parameter Conditions Typ Limit Typ Limit Typ Limit
Output Voltage 5 mA ≤ I
OUT
≤ I
OUTmax
4.85 7.76 9.70 V(Min)
5.00 4.75 8.00 7.60 10.00 9.50 V(Min)
5.15 8.24 10.30 V(Max)
5.25 8.40 10.50 V(Max)
Line Regulation (V
OUT
+ 2V) ≤ VIN≤ 26V, 15 50 24 80 30 100 mV(Max)
I
OUT
=5mA
Load Regulation 5 mA ≤ I
OUT
≤ I
OUTmax
5 50 8 80 10 100 mV(Max)
Quiescent Current (V
OUT
+ 2V) ≤ VIN≤ 26V, 2 10 2 10 2 10 mA(Max)
I
OUT
=5mA
V
IN
=(V
OUT
+ 5V), 10 20 10 20 10 20 mA(Max)
I
OUT=IOUTmax
Output Noise 10 Hz–100 kHz 150 240 300 µVrms
Voltage I
OUT
=5mA
Long Term Stability 1000 Hrs. 20 32 40 mV
Dropout Voltage I
OUT=IOUTmax
0.5 1.0 0.5 1.0 0.5 1.0 V(Max)
I
OUT
= 50 mA 110 250 110 250 110 250 mV(Max)
Short-Circuit Current 1.0 0.6 1.0 0.6 1.0 0.6 A(Min)
Peak Line Transient t
f
<
100 ms, RL= 100Ω 75 60 75 60 75 60 V(Min)
Voltage
Maximum Operational 26 26 26 V(Min)
Input Voltage
Reverse DC V
OUT
≥ −0.6V, RL= 100Ω −30 −15 −30 −15 −30 −15 V(Min)
Input Voltage
Reverse Transient t
r
<
1 ms, RL= 100Ω −75 −50 −75 −50 −75 −50 V(Min)
Input Voltage
LM2937
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Electrical Characteristics
VIN=V
NOM
+ 5V, (Note 4) I
OUTmax
= 500 mA for the TO-220 and TO-263 packages, I
OUTmax
=400mA for the SOT-223 pack-
age, C
OUT
= 10 µF unless otherwise indicated. Boldface limits apply over the entire operating temperature range of the
indicted device., all other specifications are for T
A=TJ
= 25˚C.
Output Voltage (V
OUT
) 12V 15V Units
Parameter Conditions Typ Limit Typ Limit
Output Voltage 5 mA ≤ I
OUT
≤ I
OUTmax
11.64 14.55 V (Min)
12.00 11.40 15.00 14.25 V(Min)
12.36 15.45 V(Max)
12.60 15.75 V(Max)
Line Regulation (V
OUT
+ 2V) ≤ VIN≤ 26V, 36 120 45 150 mV(Max)
I
OUT
=5mA
Load Regulation 5 mA ≤ I
OUT
≤ I
OUTmax
12 120 15 150 mV(Max)
Quiescent Current (V
OUT
+ 2V) ≤ VIN≤ 26V, 2 10 2 10 mA(Max)
I
OUT
=5mA
V
IN
=(V
OUT
+ 5V), 10 20 10 20 mA(Max)
I
OUT=IOUTmax
Output Noise 10 Hz–100 kHz, 360 450 µVrms
Voltage I
OUT
=5mA
Long Term Stability 1000 Hrs. 44 56 mV
Dropout Voltage I
OUT=IOUTmax
0.5 1.0 0.5 1.0 V(Max)
I
OUT
= 50 mA 110 250 110 250 mV(Max)
Short-Circuit Current 1.0 0.6 1.0 0.6 A(Min)
Peak Line Transient t
f
<
100 ms, RL= 100Ω 75 60 75 60 V(Min)
Voltage
Maximum Operational 26 26 V(Min)
Input Voltage
Reverse DC V
OUT
≥ −0.6V, RL= 100Ω −30 −15 −30 −15 V(Min)
Input Voltage
Reverse Transient t
r
<
1 ms, RL= 100Ω −75 −50 −75 −50 V(Min)
Input Voltage
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device
outside of its rated Operating Conditions.
Note 2: The maximum allowable power dissipation at any ambient temperature is P
MAX
= (125 − TA)/θJA, where 125 is the maximum junction temperature for op-
eration, T
A
is the ambient temperature, and θJAis the junction-to-ambient thermal resistance. If this dissipation is exceeded, the die temperature will rise above 125˚C
and the electrical specifications do not apply. If the die temperature rises above 150˚C, the LM2937 will go into thermal shutdown. For the LM2937, the
junction-to-ambient thermal resistance θ
JA
is 65˚C/W, for the TO-220 package, 73˚C/W for the TO-263 package, and 174˚C/W for the SOT-223 package. When used
with a heatsink, θ
JA
is the sum of the LM2937 junction-to-case thermal resistance θJCof 3˚C/W and the heatsink case-to-ambient thermal resistance. If the TO-263
or SOT-223 packages are used, the thermal resistance can be reduced by increasing the P.C.boardcopper area thermally connected to the package (see Application
Hints for more information on heatsinking).
Note 3: ESD rating is based on the human body model, 100 pF discharged through 1.5 kΩ.
Note 4: Typicals are at T
J
= 25˚C and represent the most likely parametric norm.
LM2937
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