National Semiconductor LM2937 Technical data

LM2937 500 mA Low Dropout Regulator

March 2000

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

SOT-223 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

TO-263 Surface-Mount Package

DS011280-5

Top View

Order Number LM2937ES-5.0, LM2937ES-8.0, LM2937ES-10, LM2937ES-12 or LM2937ES-15

See NS Package Number TS3B

DS011280-26

Front View

Order Number LM2937IMP-5.0,

LM2937IMP-8.0, LM2937IMP-10,

LM2937IMP-12 or LM2937IMP-15

See NS Package Number MP04A

DS011280-6

Side View

Connection Diagram and Ordering Information (Continued)

LM2937

Temperature

Range

−40˚C ≤ T

SOT-223 Package Markings

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.

≤ 125˚C LM2937ES-5.0 LM2937ES-8.0 LM2937ES-10 LM2937ES-12 LM2937ES-15 TS3B TO-263

≤ 85˚C LM2937IMP-5.0 LM2937IMP-8.0 LM2937IMP-10 LM2937IMP-12 LM2937IMP-15 MP04A SOT-223

5.0 8.0 10 12 15 Package

LM2937ET-5.0 LM2937ET-8.0 LM2937ET-10 LM2937ET-12 LM2937ET-15 T03B TO-220

LM2937IMPX-5.0 LM2937IMPX-8.0 LM2937IMPX-10 LM2937IMPX-12 LM2937IMPX-15 MP04A SOT-223

L71B L72B L73B L74B L75B

Output Voltage NSC Package

Drawing

in Tape

and Reel

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LM2937

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

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

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

Operating Conditions (Note 1)

Temperature Range (Note 2)

LM2937ET, LM2937ES −40˚C ≤ T LM2937IMP −40˚C ≤ T

Maximum Input Voltage 26V

≤125˚C

≤85˚C

TO-220 (10 seconds) 260˚C

Electrical Characteristics

VIN=V age, C indicated device., all other specifications are for T

Output Voltage 5 mA ≤ I

Line Regulation (V

Load Regulation 5 mA ≤ I Quiescent Current (V

Output Noise 10 Hz–100 kHz 150 240 300 µVrms Voltage I Long Term Stability 1000 Hrs. 20 32 40 mV Dropout Voltage I

Short-Circuit Current 1.0 0.6 1.0 0.6 1.0 0.6 A(Min) Peak Line Transient t Voltage Maximum Operational 26 26 26 V(Min) Input Voltage Reverse DC V Input Voltage Reverse Transient t Input Voltage

+ 5V, (Note 4) I

NOM

= 10 µF unless otherwise indicated. Boldface limits apply over the entire operating temperature range of the

OUT

Output Voltage (V

= 500 mA for the TO-220 and TO-263 packages, I

OUTmax

= 25˚C.

A=TJ

) 5V 8V 10V Units

OUT

=400mA for the SOT-223 pack-

OUTmax

Parameter Conditions Typ Limit Typ Limit Typ Limit

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)

+ 2V) ≤ VIN≤ 26V, 15 50 24 80 30 100 mV(Max)

OUT

=5mA

OUT

≤ I

OUT

OUTmax

+ 2V) ≤ VIN≤ 26V, 2 10 2 10 2 10 mA(Max)

OUT

=5mA

OUT

=(V

OUT=IOUTmax

OUT

OUT=IOUTmax

OUT

100 ms, RL= 100Ω 75 60 75 60 75 60 V(Min)

OUT

1 ms, RL= 100Ω −75 −50 −75 −50 −75 −50 V(Min)

+ 5V), 10 20 10 20 10 20 mA(Max)

OUT

=5mA

= 50 mA 110 250 110 250 110 250 mV(Max)

≥ −0.6V, RL= 100Ω −30 −15 −30 −15 −30 −15 V(Min)

5 50 8 80 10 100 mV(Max)

0.5 1.0 0.5 1.0 0.5 1.0 V(Max)

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Electrical Characteristics

VIN=V

LM2937

age, C indicted device., all other specifications are for T

Output Voltage 5 mA ≤ I

Line Regulation (V

Load Regulation 5 mA ≤ I Quiescent Current (V

Output Noise 10 Hz–100 kHz, 360 450 µVrms Voltage I Long Term Stability 1000 Hrs. 44 56 mV Dropout Voltage I

Short-Circuit Current 1.0 0.6 1.0 0.6 A(Min) Peak Line Transient t Voltage Maximum Operational 26 26 V(Min) Input Voltage Reverse DC V Input Voltage Reverse Transient t 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 eration, T 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 with a heatsink, θ 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

+ 5V, (Note 4) I

NOM

= 10 µF unless otherwise indicated. Boldface limits apply over the entire operating temperature range of the

OUT

Output Voltage (V

= 500 mA for the TO-220 and TO-263 packages, I

OUTmax

= 25˚C.

A=TJ

) 12V 15V Units

OUT

=400mA for the SOT-223 pack-

OUTmax

Parameter Conditions Typ Limit Typ Limit

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)

+ 2V) ≤ VIN≤ 26V, 36 120 45 150 mV(Max)

OUT

=5mA

OUT

≤ I

OUT

OUTmax

+ 2V) ≤ VIN≤ 26V, 2 10 2 10 mA(Max)

OUT

=5mA

OUT

=(V

OUT=IOUTmax

OUT

OUT=IOUTmax

OUT

100 ms, RL= 100Ω 75 60 75 60 V(Min)

OUT

1 ms, RL= 100Ω −75 −50 −75 −50 V(Min)

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

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

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

= 25˚C and represent the most likely parametric norm.

+ 5V), 10 20 10 20 mA(Max)

OUT

=5mA

= 50 mA 110 250 110 250 mV(Max)

≥ −0.6V, RL= 100Ω −30 −15 −30 −15 V(Min)

12 120 15 150 mV(Max)

0.5 1.0 0.5 1.0 V(Max)

= (125 − TA)/θJA, where 125 is the maximum junction temperature for op-

MAX

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