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LM2937
SNVS100F – MARCH 2000 – REVISED JULY 2014

LM2937 500-mA Low Dropout Regulator

1 Features 3 Description
•
1 Fully Specified for Operation Over −40°C to 125°C The LM2937 is a positive voltage regulator capable of
supplying up to 500 mA of load current. The use of a
• Output Current in Excess of 500 mA PNP power transistor provides a low dropout voltage
• Output Trimmed for 5% Tolerance Under all characteristic. With a load current of 500 mA the
Operating Conditions minimum input to output voltage differential required
• Typical Dropout Voltage of 0.5 V at Full Rated for the output to remain in regulation is typically 0.5 V
Load Current (1-V ensured maximum over the full operating
temperature range). Special circuitry has been
• Wide Output Capacitor ESR Range, up to 3 Ω incorporated to minimize the quiescent current to
• Internal Short Circuit and Thermal Overload typically only 10 mA with a full 500-mA load current
Protection when the input to output voltage differential is greater
• Reverse Battery Protection than 3 V.
• 60-V Input Transient Protection The LM2937 requires an output bypass capacitor for
• Mirror Image Insertion Protection stability. As with most low dropout regulators, the
ESR of this capacitor remains a critical design
parameter, but the LM2937 includes special
2 Applications compensation circuitry that relaxes ESR
• Automotive requirements. The device is stable for all ESR below
• Industrial Control 3 Ω. This allows the use of low ESR chip capacitors.
• Point-of-Load regulation Ideally suited for automotive applications, the LM2937
space will protect itself and any load circuitry from reverse
battery connections, two-battery jumps, and up to 60-
space V/−50-V load dump transients. Familiar regulator
space features such as short circuit and thermal shutdown
protection are also built in.
Simplified Schematic
Device Information(1)
PART
PACKAGE BODY SIZE (NOM)
NUMBER
TO-220 (3) 14.986 mm x 10.66 mm
LM2937 SOT (4) 6.50 mm x 3.5 mm
TO-263 (3) 10.18 mm x 8.41 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
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Table of Contents
1 Features .................................................................. 1 7.1 Overview ................................................................. 11
2 Applications ........................................................... 1 7.2 Functional Block Diagram ....................................... 11
3 Description ............................................................. 1 7.3 Feature Description................................................. 11
7.4 Device Functional Modes........................................ 12
4 Revision History..................................................... 2
5 Pin Configuration and Functions ......................... 3 8 Application and Implementation ........................ 13
8.1 Application Information............................................ 13
6 Specifications......................................................... 4
8.2 Typical Application ................................................. 13
6.1 Absolute Maximum Ratings ...................................... 4
6.2 Handling Ratings ...................................................... 4 9 Power Supply Recommendations...................... 17
6.3 Recommended Operating Conditions....................... 4 10 Layout................................................................... 18
6.4 Thermal Information .................................................. 4 10.1 Layout Guidelines ................................................. 18
6.5 Electrical Characteristics: LM2937-5 ........................ 5 10.2 Layout Example .................................................... 18
6.6 Electrical Characteristics: LM2937-8 ........................ 5 11 Device and Documentation Support ................. 19
6.7 Electrical Characteristics: LM2937-10 ...................... 5 11.1 Trademarks ........................................................... 19
6.8 Electrical Characteristics: LM2937-12 ...................... 7 11.2 Electrostatic Discharge Caution ............................ 19
6.9 Electrical Characteristics: LM2937-15 ...................... 7 11.3 Glossary ................................................................ 19
6.10 Typical Characteristics ............................................ 8 12 Mechanical, Packaging, and Orderable
7 Detailed Description ............................................ 11 Information ........................................................... 19

4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.

Changes from Revision E (June 2013) to Revision F Page

• Changed format to meet new TI standards; added Device Information and Handling Ratings tables; updated
connection drawings; rename Functional Description and Applications sections, reformat and add new information,
add Devices and Documentation section .............................................................................................................................. 1

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5 Pin Configuration and Functions

TO-220 Plastic Package (NDE)

3
Top View

INPUT 1

GND 2

OUTPUT 3 TAB

SOT-223 Plastic Package (DCY)

4
Top View

INPUT 1

4
GND 2
(TAB)

OUTPUT 3

DDPAK/TO-263 Surface-Mount Package (KTT)

3
Top View

INPUT 1
TAB

GND 2

OUTPUT 3

Pin Functions
PIN
I/O DESCRIPTION
NAME NDE KTT DCY
INPUT 1 1 1 I Unregulated voltage input
GND 2 2 2 — Ground
Regulated voltage output. This pin requires an output capacitor to
OUTPUT 3 3 3 O maintain stability. See the Detailed Design Procedure section for output
capacitor details.
Thermal and ground connection. Connect the TAB to a large copper
area to remove heat from the device. The TAB is internally connected
GND TAB TAB 4 —
to device pin 2 (GND). Connect the TAB to GND or leave floating. Do
not connect the TAB to any potential other than GND at device pin 2.

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6 Specifications
6.1 Absolute Maximum Ratings (1) (2)
over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
Continuous 26
Input voltage (VIN) V
Transient (t ≤ 100 ms) 60
Internal power dissipation (3) Internally limited
Maximum junction temperature 150 °C

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
(3) The maximum allowable power dissipation at any ambient temperature is PMAX = (125°C − TA)/RθJA, where 125 is the maximum junction
temperature for operation, TA is the ambient temperature, and RθJA is 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.

6.2 Handling Ratings

MIN MAX UNIT
Tstg Storage temperature range −65 150 °C
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all –2000 2000
V(ESD) Electrostatic discharge V
pins (1)

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions (1)

over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT

(2)
LM2937ET (NDE), LM2937ES (KTT) −40 125
Junction temperature (TJ) °C
LM2937IMP (DCY) −40 85
Input voltage (VIN) VOUT + 1V 26 V

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) The maximum allowable power dissipation at any ambient temperature is PMAX = (125°C − TA)/RθJA, where 125°C is the maximum
junction temperature for operation, TA is the ambient temperature, and RθJA is 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.

6.4 Thermal Information

LM2937
THERMAL METRIC (1) NDE (2) KTT DCY UNIT
3 PINS 3 PINS 4 PINS
RθJA Junction-to-ambient thermal resistance 77.9 41.8 58.3
RθJC(top) Junction-to-case (top) thermal resistance 35.5 43.5 39.2
RθJB Junction-to-board thermal resistance 70.6 0.8 N/A
°C/W
ψJT Junction-to-top characterization parameter 13 23.5 7
ψJB Junction-to-board characterization parameter 70.6 10.3 1.6
RθJC(bot) Junction-to-case (bottom) thermal resistance 1 22.5 22.5

(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
(2) Thermal information for the TO-220 package is for a free-standing package vertically mounted in the middle of a PCB which is compliant
to the JEDEC HIGH-K 2s2p (JESD51-7) specifications. No additional heat sink is attached. See Heatsinking TO-220 Package Parts
section for more information.

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6.5 Electrical Characteristics: LM2937-5

Unless otherwise specified: VIN = VOUT(NOM) + 5 V; IOUT(MAX) = 500 mA for the TO-220 and DDPAK/TO-263 packages; IOUT(MAX)
= 400 mA for the SOT-223 package; and COUT = 10 μF. Conditions and the associated minimum and maximum limits apply
over the Recommended Operating temperature range for the specific package, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
Output voltage TA = TJ = 25°C, 5 mA ≤ IOUT ≤ IOUT(MAX) 4.85 5 5.15 V
5 mA ≤ IOUT ≤ IOUT(MAX) 4.75 5 5.25 V
Line regulation (VOUT + 2 V) ≤ VIN ≤ 26 V, IOUT = 5 mA 15 50 mV
Load regulation 5 mA ≤ IOUT ≤ IOUT(MAX) 5 50 mV
Quiescent Current (VOUT + 2 V) ≤ VIN ≤ 26 V, IOUT = 5 mA 2 10 mA
VIN = (VOUT + 5 V), IOUT = IOUT(MAX) 10 20 mA
Output noise voltage 10 Hz to 100 kHz, IOUT = 5 mA 150 μVrms
Long-term stability 1000 Hrs. 20 mV
Dropout voltage IOUT = IOUT(MAX) 0.5 1 V
IOUT = 50 mA 110 250 mV
Short-circuit current 0.6 1 A
Peak line transient voltage tf < 100 ms, RL = 100 Ω 60 75 V
Maximum operational input voltage 26 V
Reverse DC input voltage VOUT ≥ −0.6 V, RL = 100 Ω –15 –30 V
Reverse transient input voltage tr < 1 ms, RL = 100 Ω –50 –75 V

6.6 Electrical Characteristics: LM2937-8

Unless otherwise specified: VIN = VOUT(NOM) + 5 V; IOUT(MAX) = 500 mA for the TO-220 and DDPAK/TO-263 packages; IOUT(MAX)
= 400 mA for the SOT-223 package; and COUT = 10 μF. Conditions and the associated Minimum and Maximum limits apply
over the Recommended Operating temperature range for the specific package, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
Output voltage TA = TJ = 25°C, 5 mA ≤ IOUT ≤ IOUT(MAX) 7.76 8 8.24 V
5 mA ≤ IOUT ≤ IOUT(MAX) 7.6 8 8.4 V
Line regulation (VOUT + 2 V) ≤ VIN ≤ 26 V, IOUT = 5 mA 24 80 mV
Load regulation 5 mA ≤ IOUT ≤ IOUT(MAX) 8 80 mV
Quiescent Current (VOUT + 2 V) ≤ VIN ≤ 26 V, IOUT = 5 mA 2 10 mA
VIN = (VOUT + 5 V), IOUT = IOUT(MAX) 10 20 mA
Output noise voltage 10 Hz to 100 kHz, IOUT = 5 mA 240 μVrms
Long-term stability 1000 Hrs. 32 mV
Dropout voltage IOUT = IOUT(MAX) 0.5 1 V
IOUT = 50 mA 110 250 mV
Short-circuit current 0.6 1 A
Peak line transient voltage tf < 100 ms, RL = 100 Ω 60 75 V
Maximum operational input voltage 26 V
Reverse DC input voltage VOUT ≥ −0.6 V, RL = 100 Ω –15 –30 V
Reverse transient input voltage tr < 1 ms, RL = 100 Ω –50 –75 V

6.7 Electrical Characteristics: LM2937-10

Unless otherwise specified: VIN = VOUT(NOM) + 5 V; IOUT(MAX) = 500 mA for the TO-220 and DDPAK/TO-263 packages; IOUT(MAX)
= 400 mA for the SOT-223 package; and COUT = 10 μF. Conditions and the associated Minimum and Maximum limits apply
over the Recommended Operating temperature range for the specific package, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
Output voltage TA = TJ = 25°C, 5 mA ≤ IOUT ≤ IOUT(MAX) 9.7 10 10.3 V
5 mA ≤ IOUT ≤ IOUT(MAX) 9.5 10 10.5 V
Line regulation (VOUT + 2V) ≤ VIN ≤ 26V, IOUT = 5 mA 30 100 mV

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Electrical Characteristics: LM2937-10 (continued)

Unless otherwise specified: VIN = VOUT(NOM) + 5 V; IOUT(MAX) = 500 mA for the TO-220 and DDPAK/TO-263 packages; IOUT(MAX)
= 400 mA for the SOT-223 package; and COUT = 10 μF. Conditions and the associated Minimum and Maximum limits apply
over the Recommended Operating temperature range for the specific package, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
Load regulation 5 mA ≤ IOUT ≤ IOUT(MAX) 10 100 mV
Quiescent Current (VOUT + 2V) ≤ VIN ≤ 26V, IOUT = 5 mA 2 10 mA
VIN = (VOUT + 5V), IOUT = IOUT(MAX) 10 20 mA
Output noise voltage 10 Hz to 100 kHz, IOUT = 5 mA 300 μVrms
Long-term stability 1000 Hrs. 40 mV
Dropout voltage IOUT = IOUT(MAX) 0.5 1 V
IOUT = 50 mA 110 250 mV
Short-circuit current 0.6 1 A
Peak line transient voltage tf < 100 ms, RL = 100 Ω 60 75 V
Maximum operational input voltage 26 V
Reverse DC input voltage VOUT ≥ −0.6 V, RL = 100 Ω –15 –30 V
Reverse transient input voltage tr < 1 ms, RL = 100 Ω –50 –75 V

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6.8 Electrical Characteristics: LM2937-12

Unless otherwise specified: VIN = VOUT(NOM) + 5 V; IOUT(MAX) = 500 mA for the TO-220 and DDPAK/TO-263 packages; IOUT(MAX)
= 400 mA for the SOT-223 package; and COUT = 10 μF. Conditions and the associated Minimum and Maximum limits apply
over the Recommended Operating temperature range for the specific package, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
Output voltage TA = TJ = 25°C, 5 mA ≤ IOUT ≤ IOUT(MAX) 11.64 12 12.36 V
5 mA ≤ IOUT ≤ IOUT(MAX) 11.4 12 12.6 V
Line regulation (VOUT + 2V) ≤ VIN ≤ 26V, IOUT = 5 mA 36 120 mV
Load regulation 5 mA ≤ IOUT ≤ IOUT(MAX) 12 120 mV
Quiescent Current (VOUT + 2V) ≤ VIN ≤ 26V, IOUT = 5 mA 2 10 mA
VIN = (VOUT + 5V), IOUT = IOUT(MAX) 10 20 mA
Output noise voltage 10 Hz to 100 kHz, IOUT = 5 mA 360 μVrms
Long-term stability 1000 Hrs. 44 mV
Dropout voltage IOUT = IOUT(MAX) 0.5 1 V
IOUT = 50 mA 110 250 mV
Short-circuit current 0.6 1 A
Peak line transient voltage tf < 100 ms, RL = 100 Ω 60 75 V
Maximum operational input voltage 26 V
Reverse DC input voltage VOUT ≥ −0.6 V, RL = 100 Ω –15 –30 V
Reverse transient input voltage tr < 1 ms, RL = 100 Ω –50 –75 V

6.9 Electrical Characteristics: LM2937-15

Unless otherwise specified: VIN = VOUT(NOM) + 5 V; IOUT(MAX) = 500 mA for the TO-220 and DDPAK/TO-263 packages; IOUT(MAX)
= 400 mA for the SOT-223 package; and COUT = 10 μF. Conditions and the associated Minimum and Maximum limits apply
over the Recommended Operating temperature range for the specific package, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
Output voltage TA = TJ = 25°C, 5 mA ≤ IOUT ≤ IOUT(MAX) 14.55 15 15.45 V
5 mA ≤ IOUT ≤ IOUT(MAX) 14.25 15 15.75 V
Line regulation (VOUT + 2V) ≤ VIN ≤ 26V, IOUT = 5 mA 45 150 mV
Load regulation 5 mA ≤ IOUT ≤ IOUT(MAX) 15 150 mV
Quiescent Current (VOUT + 2V) ≤ VIN ≤ 26V, IOUT = 5 mA 2 10 mA
VIN = (VOUT + 5V), IOUT = IOUT(MAX) 10 20 mA
Output noise voltage 10 Hz to 100 kHz, IOUT = 5 mA 450 μVrms
Long-term stability 1000 Hrs. 56 mV
Dropout voltage IOUT = IOUT(MAX) 0.5 1 V
IOUT = 50 mA 110 250 mV
Short-circuit current 0.6 1 A
Peak line transient voltage tf < 100 ms, RL = 100 Ω 60 75 V
Maximum operational input voltage 26 V
Reverse DC input voltage VOUT ≥ −0.6 V, RL = 100 Ω –15 –30 V
Reverse transient input voltage tr < 1 ms, RL = 100 Ω –50 –75 V

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6.10 Typical Characteristics

Figure 1. Dropout Voltage vs. Output Current Figure 2. Dropout Voltage vs. Temperature

Figure 3. Output Voltage vs. Temperature Figure 4. Quiescent Current vs. Temperature

Figure 5. Quiescent Current vs. Input Voltage Figure 6. Quiescent Current vs. Output Current

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Typical Characteristics (continued)

Figure 7. Line Transient Response Figure 8. Load Transient Response

Figure 9. Ripple Rejection Figure 10. Output Impedence

Figure 11. Maximum Power Dissipation (TO-220)1 Figure 12. Maximum Power Dissipation (DDPAK/TO-263)

1. The maximum allowable power dissipation at any ambient temperature is PMAX = (125°C − TA)/RθJA, where 125 is
the maximum junction temperature for operation, TA is the ambient temperature, and RθJA is 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.

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Typical Characteristics (continued)

Figure 13. Low-Voltage Behavior Figure 14. Low-Voltage Behavior

Figure 15. Output at Voltage Extremes Figure 16. Output Capacitor ESR

Figure 17. Peak Output Current

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7 Detailed Description

7.1 Overview
The LM2937 is a positive voltage regulator capable of supplying up to 500 mA of load current. The use of a PNP
power transistor provides a low dropout voltage characteristic. With a load current of 500 mA the minimum input
to output voltage differential required for the output to remain in regulation is typically 0.5 V (1 V ensured
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 3 V.

7.2 Functional Block Diagram

INPUT OUTPUT
PNP

OVSD Thermal
Current Limit
(§32V) Shutdown

Bandgap
Reference

LM2937

GND

7.3 Feature Description

7.3.1 Thermal Shutdown (TSD)
The Thermal Shutdown circuitry of the LM2937 has been designed to protect the device against temporary
thermal overload conditions. The TSD circuitry is not intended to replace proper heat-sinking. Continuously
running the LM2937 device at thermal shutdown may degrade device reliability as the junction temperature will
be exceeding the absolute maximum junction temperature rating.

7.3.2 Short Circuit Current Limit

The output current limiting circuitry of the LM2937 has been designed to limit the output current in cases where
the load impedance is unusually low. This includes situations where the output may be shorted directly to ground.
Continuous operation of the LM2937 at the current limit will typically result in the LM2937 transitioning into
Thermal Shutdown mode.

7.3.3 Overvoltage Shutdown (OVSD)

Input voltages greater than typically 32 V will cause the LM2937 output to be disabled. When operating with the
input voltage greater than the maximum recommended input voltage of 26 V the device performance is not
ensured. Continuous operation with the input voltage greater than the maximum recommended input voltage is
discouraged.

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7.4 Device Functional Modes

The LM2937 design does not include any undervoltage lock-out (UVLO), or enable functions. Generally, the
output voltage will track the input voltage until the input voltage is greater than VOUT + 1V. When the input
voltage is greater than VOUT + 1V the LM2937 will be in linear operation, and the output voltage will be regulated;
however, the device will be sensitive to any small perturbation of the input voltage. Device dynamic performance
is improved when the input voltage is at least 2 V greater than the output voltage.

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8 Application and Implementation

8.1 Application Information
Figure 18 shows the typical application circuit for the LM2937. The output capacitor, COUT, must have a
capacitance value of at least 10 µF with an ESR of at least 10 mΩ, but no more than 3 Ω. The minimum
capacitance value, and the ESR requirements apply across the entire expected operating ambient temperature
range.

8.2 Typical Application

Figure 18. LM2937 Typical Application

*Required if the regulator is located more than 3 inches from the power-supply-filter capacitors.
**Required for stability. COUT must be at least 10 µF (over full expected operating temperature range) and
located as close as possible to the regulator. The equivalent series resistance, ESR, of this capacitor may be
as high as 3 Ω.

8.2.1 Design Requirements

For this design example, use the parameters listed in Table 1:

Table 1. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
Output voltage 8V
Input voltage 10 V to 26 V
5 mA to IOUT(MAX) (see Electrical Characteristics: LM2937-5, Electrical
Characteristics: LM2937-8, Electrical Characteristics: LM2937-10,
Output current requirement
Electrical Characteristics: LM2937-12, Electrical Characteristics:
LM2937-15 for details)
Input capacitor value 0.1 µF
Output capacitor capacitance
10 µF minimum
value
Output capacitor ESR value 0.01 Ω to 3 Ω

8.2.2 Detailed Design Procedure

8.2.2.1 External Capacitors

The output capacitor is critical to maintaining regulator stability, and must meet the required conditions for both
Equivalent Series Resistance (ESR) and minimum amount of capacitance.
Minimum Capacitance:
The minimum output capacitance required to maintain stability is 10 μF. (This value may be increased without
limit.) Larger values of output capacitance will give improved transient response.
ESR Limits:
The ESR of the output capacitor will cause loop instability if it is too high or too low. The acceptable range of
ESR plotted versus load current is shown in the graph below. It is essential that the output capacitor meet
these requirements, or oscillations can result.

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8.2.2.2 Output Capacitor ESR

Figure 19. ESR Limits

It is important to note that for most capacitors, ESR is specified only at room temperature. However, the designer
must ensure that the ESR will stay inside the limits shown over the entire operating temperature range for the
design.
For aluminum electrolytic capacitors, ESR will increase by about 30X as the temperature is reduced from 25°C to
−40°C. This type of capacitor is not well-suited for low temperature operation.
Solid tantalum capacitors have a more stable ESR over temperature, but are more expensive than aluminum
electrolytics. A cost-effective approach sometimes used is to parallel an aluminum electrolytic with a solid
Tantalum, with the total capacitance split about 75/25% with the Aluminum being the larger value.
If two capacitors are paralleled, the effective ESR is the parallel of the two individual values. The “flatter” ESR of
the Tantalum will keep the effective ESR from rising as quickly at low temperatures.

8.2.2.3 Heatsinking
A heatsink may be required depending on the maximum power dissipation and maximum ambient temperature of
the application. Under all possible operating conditions, the junction temperature must be within the range
specified under Absolute Maximum Ratings.
To determine if a heatsink is required, the power dissipated by the regulator, PD, must be calculated.
Figure 20 below shows the voltages and currents which are present in the circuit, as well as the formula for
calculating the power dissipated in the regulator:

IIN = IL + IG
PD = (VIN − VOUT) IL + (VIN) IG

Figure 20. Power Dissipation Diagram

The next parameter which must be calculated is the maximum allowable temperature rise, TR (max). This is
calculated by using the formula:
TR (max) = TJ(max) − TA (max)

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where
• TJ (max) is the maximum allowable junction temperature, which is 125°C for the TO-220 and TO-263
packages, and 85°C for the SOT-223 package.
• TA (max) is the maximum ambient temperature which will be encountered in the application. (1)
Using the calculated values for TR(max) and PD, the maximum allowable value for the junction-to-ambient
thermal resistance, RθJA, can now be found:
RθJA = TR (max)/PD (2)

NOTE
IMPORTANT: If the maximum allowable value for RθJA is found to be ≥ 53°C/W for the
TO-220 package, ≥ 80°C/W for the DDPAK/TO-263 package, or ≥ 174°C/W for the SOT-
223 package, no heatsink is needed since the package alone will dissipate enough heat to
satisfy these requirements.
If the calculated value for R θJA falls below these limits, a heatsink is required.

8.2.2.4 Heatsinking TO-220 Package Parts

The TO-220 can be attached to a typical heatsink, or secured to a copper plane on a PC board. If a copper plane
is to be used, the values of RθJA will be the same as shown in the next section for the DDPAK/TO-263.
If a manufactured heatsink is to be selected, the value of heatsink-to-ambient thermal resistance, RθHA, must first
be calculated:
RθHA = RθJA − RθCH − RθJC
where
• RθJC is defined as the thermal resistance from the junction to the surface of the case. A value of 3°C/W can be
assumed for RθJC for this calculation
• RθCH is defined as the thermal resistance between the case and the surface of the heatsink. The value of RθCH
will vary from about 1.5°C/W to about 2.5°C/W (depending on method of attachment, insulator, etc.). If the
exact value is unknown, 2°C/W should be assumed for RθCH (3)
When a value for RθHA is found using the equation shown, a heatsink must be selected that has a value that is
less than or equal to this number.
RθHA is specified numerically by the heatsink manufacturer in the catalog, or shown in a curve that plots
temperature rise vs power dissipation for the heatsink.

8.2.2.5 Heatsinking DDPAK/TO-263 and SOT-223 Package Parts

Both the DDPAK/TO-263 and SOT-223 packages use a copper plane on the PCB and the PCB itself as a
heatsink. To optimize the heat sinking ability of the plane and PCB, solder the tab of the package to the plane.
Figure 21 shows for the DDPAK/TO-263 the measured values of RθJA for different copper area sizes using a
typical PCB with 1 ounce copper and no solder mask over the copper area used for heatsinking.

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Figure 21. RθJA vs. Copper (1 ounce) Area for the DDPAK/TO-263 Package

As shown in Figure 21, increasing the copper area beyond 1 square inch produces very little improvement. It
should also be observed that the minimum value of RθJA for the DDPAK/TO-263 package mounted to a PCB is
32°C/W.
As a design aid, Figure 22 shows the maximum allowable power dissipation compared to ambient temperature
for the DDPAK/TO-263 device (assuming RθJA is 35°C/W and the maximum junction temperature is 125°C).

Figure 22. Maximum Power Dissipation vs. TAMB for the DDPAK/TO-263 Package

Figure 23 and Figure 24 show information for the SOT-223 package. Figure 24 assumes an RθJA of 74°C/W for 1
ounce copper and 51°C/W for 2 ounce copper and a maximum junction temperature of 85°C.

16 Submit Documentation Feedback Copyright © 2000–2014, Texas Instruments Incorporated

Product Folder Links: LM2937

 LM2937
www.ti.com SNVS100F – MARCH 2000 – REVISED JULY 2014

Figure 23. RθJA vs Copper (2 ounce) Area for the Figure 24. Maximum Power Dissipation vs TAMB for
SOT-223 Package the SOT-223 Package

8.2.2.6 SOT-223 Soldering Recommendations

It is not recommended to use hand soldering or wave soldering to attach the small SOT-223 package to a printed
circuit board. The excessive temperatures involved may cause package cracking.
Either vapor phase or infrared reflow techniques are preferred soldering attachment methods for the SOT-223
package.

8.2.3 Application Curves

Figure 25. Output at Voltage Extremes Figure 26. Dropout Voltage vs. Temperature

9 Power Supply Recommendations

This device is designed to operate from an input supply voltage from at least VOUT + 1 V up to a maximum of 26
V. The input supply should be well regulated and free of spurious noise. To ensure that the LM2937 output
voltage is well regulated the input supply should be at least VOUT + 2 V. A capacitor at the INPUT pin may not be
specifically required if the bulk input supply filter capacitors are within three inches of the INPUT pin, but adding
one will not be detrimental to operation.

Copyright © 2000–2014, Texas Instruments Incorporated Submit Documentation Feedback 17

Product Folder Links: LM2937
LM2937
SNVS100F – MARCH 2000 – REVISED JULY 2014 www.ti.com

10 Layout

10.1 Layout Guidelines

The dynamic performance of the LM2937 is dependent on the layout of the PCB. PCB layout practices that are
adequate for typical LDO's may degrade the PSRR, noise, or transient performance of the LM2937. Best
performance is achieved by placing CIN and COUT on the same side of the PCB as the LM2937, and as close as
is practical to the package. The ground connections for CIN and COUT should be back to the LM2937 ground pin
using as wide, and as short, of a copper trace as is practical.
Connections using long trace lengths, narrow trace widths, and/or connections through vias should be avoided
as these will add parasitic inductances and resistances that will give inferior performance, especially during
transient conditions

10.2 Layout Example

CIN COUT
1

INPUT OUTPUT

GND

Figure 27. LM2937 SOT-223-4 Layout

18 Submit Documentation Feedback Copyright © 2000–2014, Texas Instruments Incorporated

Product Folder Links: LM2937

 LM2937
www.ti.com SNVS100F – MARCH 2000 – REVISED JULY 2014

11 Device and Documentation Support

11.1 Trademarks
All trademarks are the property of their respective owners.
11.2 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.

11.3 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.

12 Mechanical, Packaging, and Orderable Information

The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.

Copyright © 2000–2014, Texas Instruments Incorporated Submit Documentation Feedback 19

Product Folder Links: LM2937
 PACKAGE OPTION ADDENDUM

www.ti.com 1-Oct-2021

PACKAGING INFORMATION

Orderable Device Status Package Type Package Pins Package Eco Plan Lead finish/ MSL Peak Temp Op Temp (°C) Device Marking Samples
(1) Drawing Qty (2) Ball material (3) (4/5)
(6)

LM2937ES-10/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES

TO-263 & Green -10
LM2937ES-12 NRND DDPAK/ KTT 3 45 Non-RoHS Call TI Level-3-235C-168 HR -40 to 125 LM2937ES
TO-263 & Green -12
LM2937ES-12/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -12
LM2937ES-15 NRND DDPAK/ KTT 3 45 Non-RoHS Call TI Level-3-235C-168 HR -40 to 125 LM2937ES
TO-263 & Green -15
LM2937ES-15/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -15
LM2937ES-2.5/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -2.5
LM2937ES-3.3 NRND DDPAK/ KTT 3 45 Non-RoHS Call TI Level-3-235C-168 HR -40 to 125 LM2937ES
TO-263 & Green -3.3
LM2937ES-3.3/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -3.3
LM2937ES-5.0 NRND DDPAK/ KTT 3 45 Non-RoHS Call TI Level-3-235C-168 HR -40 to 125 LM2937ES
TO-263 & Green -5.0
LM2937ES-5.0/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -5.0
LM2937ES-8.0/NOPB ACTIVE DDPAK/ KTT 3 45 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -8.0
LM2937ESX-12/NOPB ACTIVE DDPAK/ KTT 3 500 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -12
LM2937ESX-15/NOPB ACTIVE DDPAK/ KTT 3 500 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -15
LM2937ESX-3.3 NRND DDPAK/ KTT 3 500 Non-RoHS Call TI Level-3-235C-168 HR -40 to 125 LM2937ES
TO-263 & Green -3.3
LM2937ESX-3.3/NOPB ACTIVE DDPAK/ KTT 3 500 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -3.3
LM2937ESX-5.0 NRND DDPAK/ KTT 3 500 Non-RoHS Call TI Level-3-235C-168 HR -40 to 125 LM2937ES
TO-263 & Green -5.0

Addendum-Page 1
 PACKAGE OPTION ADDENDUM

www.ti.com 1-Oct-2021

Orderable Device Status Package Type Package Pins Package Eco Plan Lead finish/ MSL Peak Temp Op Temp (°C) Device Marking Samples
(1) Drawing Qty (2) Ball material (3) (4/5)
(6)

LM2937ESX-5.0/NOPB ACTIVE DDPAK/ KTT 3 500 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -5.0
LM2937ESX-8.0/NOPB ACTIVE DDPAK/ KTT 3 500 RoHS-Exempt SN Level-3-245C-168 HR -40 to 125 LM2937ES
TO-263 & Green -8.0
LM2937ET-10/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2937ET
-10
LM2937ET-12 NRND TO-220 NDE 3 45 Non-RoHS Call TI Level-1-NA-UNLIM -40 to 125 LM2937ET
& Green -12
LM2937ET-12/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2937ET
-12
LM2937ET-15 NRND TO-220 NDE 3 45 Non-RoHS Call TI Level-1-NA-UNLIM -40 to 125 LM2937ET
& Green -15
LM2937ET-15/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2937ET
-15
LM2937ET-2.5/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2937ET
-2.5
LM2937ET-3.3 NRND TO-220 NDE 3 45 Non-RoHS Call TI Level-1-NA-UNLIM -40 to 125 LM2937ET
& Green -3.3
LM2937ET-3.3/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2937ET
-3.3
LM2937ET-5.0 NRND TO-220 NDE 3 45 Non-RoHS Call TI Level-1-NA-UNLIM -40 to 125 LM2937ET
& Green -5.0
LM2937ET-5.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS-Exempt SN Level-1-NA-UNLIM -40 to 125 LM2937ET
& Green -5.0
LM2937ET-8.0 NRND TO-220 NDE 3 45 Non-RoHS Call TI Level-1-NA-UNLIM -40 to 125 LM2937ET
& Green -8.0
LM2937ET-8.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2937ET
-8.0
LM2937IMP-10 NRND SOT-223 DCY 4 1000 Non-RoHS Call TI Level-1-260C-UNLIM -40 to 85 L73B
& Green
LM2937IMP-10/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L73B

LM2937IMP-12 NRND SOT-223 DCY 4 1000 Non-RoHS Call TI Level-1-260C-UNLIM -40 to 85 L74B
& Green
LM2937IMP-12/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L74B

Addendum-Page 2
 PACKAGE OPTION ADDENDUM

www.ti.com 1-Oct-2021

Orderable Device Status Package Type Package Pins Package Eco Plan Lead finish/ MSL Peak Temp Op Temp (°C) Device Marking Samples
(1) Drawing Qty (2) Ball material (3) (4/5)
(6)

LM2937IMP-2.5/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L68B

LM2937IMP-3.3 NRND SOT-223 DCY 4 1000 Non-RoHS Call TI Level-1-260C-UNLIM -40 to 85 L69B
& Green
LM2937IMP-3.3/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L69B

LM2937IMP-5.0 NRND SOT-223 DCY 4 1000 Non-RoHS Call TI Level-1-260C-UNLIM -40 to 85 L71B
& Green
LM2937IMP-5.0/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L71B

LM2937IMP-8.0/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L72B

LM2937IMPX-10/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L73B

LM2937IMPX-12/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L74B

LM2937IMPX-15/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L75B

LM2937IMPX-2.5/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L68B

LM2937IMPX-3.3 NRND SOT-223 DCY 4 2000 Non-RoHS Call TI Level-1-260C-UNLIM -40 to 85 L69B
& Green
LM2937IMPX-3.3/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L69B

LM2937IMPX-5.0/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L71B

LM2937IMPX-8.0 NRND SOT-223 DCY 4 2000 Non-RoHS Call TI Level-1-260C-UNLIM -40 to 85 L72B
& Green
LM2937IMPX-8.0/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L72B

(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.

Addendum-Page 3
 PACKAGE OPTION ADDENDUM

www.ti.com 1-Oct-2021

(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.

(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.

(6)
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 4
 PACKAGE MATERIALS INFORMATION

www.ti.com 17-Dec-2019

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1
Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
LM2937ESX-12/NOPB DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937ESX-15/NOPB DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937ESX-3.3 DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937ESX-3.3/NOPB DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937ESX-5.0 DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937ESX-5.0/NOPB DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937ESX-8.0/NOPB DDPAK/ KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
TO-263
LM2937IMP-10 SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-10/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-12 SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-12/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-2.5/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-3.3 SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3

Pack Materials-Page 1
 PACKAGE MATERIALS INFORMATION

www.ti.com 17-Dec-2019

Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1

Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
LM2937IMP-3.3/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-5.0 SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-5.0/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMP-8.0/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-10/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-12/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-15/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-2.5/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-3.3 SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-3.3/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-5.0/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-8.0 SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2937IMPX-8.0/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3

*All dimensions are nominal

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM2937ESX-12/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2937ESX-15/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2937ESX-3.3 DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2937ESX-3.3/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0

Pack Materials-Page 2
 PACKAGE MATERIALS INFORMATION

www.ti.com 17-Dec-2019

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM2937ESX-5.0 DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2937ESX-5.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2937ESX-8.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2937IMP-10 SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-10/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-12 SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-12/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-2.5/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-3.3 SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-3.3/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-5.0 SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-5.0/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMP-8.0/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2937IMPX-10/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-12/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-15/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-2.5/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-3.3 SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-3.3/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-5.0/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-8.0 SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2937IMPX-8.0/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0

Pack Materials-Page 3
 MECHANICAL DATA

MPDS094A – APRIL 2001 – REVISED JUNE 2002

DCY (R-PDSO-G4) PLASTIC SMALL-OUTLINE

6,70 (0.264)
6,30 (0.248)
3,10 (0.122)
2,90 (0.114)
4
0,10 (0.004) M

7,30 (0.287) 3,70 (0.146)

6,70 (0.264) 3,30 (0.130)

Gauge Plane
1 2 3
0,25 (0.010)
0,84 (0.033) 0°–10°
2,30 (0.091)
0,66 (0.026)
0,10 (0.004) M
4,60 (0.181) 0,75 (0.030) MIN

1,70 (0.067)
1,80 (0.071) MAX 1,50 (0.059)
0,35 (0.014)
0,23 (0.009)
Seating Plane

0,10 (0.0040) 0,08 (0.003)

0,02 (0.0008)

4202506/B 06/2002

NOTES: A. All linear dimensions are in millimeters (inches).

B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion.
D. Falls within JEDEC TO-261 Variation AA.

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

 MECHANICAL DATA
NDE0003B

www.ti.com
 MECHANICAL DATA
KTT0003B

TS3B (Rev F)
BOTTOM SIDE OF PACKAGE

www.ti.com
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