VIN
Unregulated Input VOUT
Regulated Output
C1*
0.47 µF COUT**
22 µF
LM2940
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LM2940x 1-A Low Dropout Regulator
1 Features 3 Description
The LM2940-N and LM2940C positive voltage
1 Input Voltage Range = 6 V to 26 V regulators feature the ability to source 1 A of output
Dropout Voltage Typically 0.5 V at IOUT =1A current with a dropout voltage of typically 0.5 V and a
Output Current in Excess of 1 A maximum of 1 V over the entire temperature range.
Furthermore, a quiescent current reduction circuit has
Output Voltage Trimmed Before Assembly been included which reduces the ground current
Reverse Battery Protection when the differential between the input voltage and
Internal Short Circuit Current Limit the output voltage exceeds approximately 3 V. The
quiescent current with 1 A of output current and an
Mirror Image Insertion Protection input-output differential of 5 V is therefore only 30
P+Product Enhancement Tested mA. Higher quiescent currents only exist when the
regulator is in the dropout mode (VIN VOUT 3 V).
2 Applications Designed also for vehicular applications, the LM2940-
Post Regulator for Switching Supplies N and LM2940C and all regulated circuitry are
Logic Power Supplies protected from reverse battery installations or 2-
Industrial Instrumentation battery jumps. During line transients, such as load
dump when the input voltage can momentarily
space exceed the specified maximum operating voltage, the
space regulator will automatically shut down to protect both
space the internal circuits and the load. The LM2940-N and
LM2940C cannot be harmed by temporary mirror-
image insertion. Familiar regulator features such as
short circuit and thermal overload protection are also
provided.
Device Information(1)
PART NUMBER PACKAGE BODY SIZE (NOM)
SOT-223 (4) 6.50 mm x 3.50 mm
WSON (8) 4.00 mm x 4.00 mm
LM2940-N TO-263 (3) 10.18 mm x 8.41 mm
TO-220 (3) 14.986 mm x 10.16 mm
TO-263 (3) 10.18 mm x 8.41 mm
LM2940C TO-220 (3) 14.986 mm x 10.16 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Simplified Schematic
*Required if regulator is located far from power supply filter.
**COUT must be at least 22 μF to maintain stability. May be increased without bound to maintain regulation during
transients. Locate as close as possible to the regulator. This capacitor must be rated over the same operating
temperature range as the regulator and the ESR is critical; see curve.
1
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
7.3 Feature Description................................................. 13
1 Features.................................................................. 17.4 Device Functional Modes........................................ 14
2 Applications ........................................................... 18 Application and Implementation ........................ 15
3 Description............................................................. 18.1 Application Information............................................ 15
4 Revision History..................................................... 28.2 Typical Application.................................................. 15
5 Pin Configuration and Functions......................... 39 Power Supply Recommendations...................... 17
6 Specifications......................................................... 410 Layout................................................................... 17
6.1 Absolute Maximum Ratings ...................................... 410.1 Layout Guidelines ................................................. 17
6.2 ESD Ratings.............................................................. 410.2 Layout Examples................................................... 17
6.3 Recommended Operating Conditions....................... 410.3 Heatsinking ........................................................... 18
6.4 Thermal Information.................................................. 511 Device and Documentation Support................. 20
6.5 Electrical Characteristics (5 V and 8 V).................... 511.1 Documentation Support ........................................ 20
6.6 Electrical Characteristics (9 V and 10 V).................. 611.2 Related Links ........................................................ 20
6.7 Electrical Characteristics (12 V and 15 V)................ 711.3 Trademarks........................................................... 20
6.8 Typical Characteristics.............................................. 811.4 Electrostatic Discharge Caution............................ 20
7 Detailed Description............................................ 13 11.5 Glossary................................................................ 20
7.1 Overview................................................................. 13 12 Mechanical, Packaging, and Orderable
7.2 Functional Block Diagram....................................... 13 Information ........................................................... 20
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision I (April 2013) to Revision J Page
Added Pin Configuration and Functions section, ESD Rating table, Feature Description section, Device Functional
Modes,Application and Implementation section, Power Supply Recommendations section, Layout section, Device
and Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1
Deleted information re: obsolete CDIP and CLGA package options ; Change pin names from Vin, Vout to IN, OUT;
delete Heatsinking sections re: packages apart from TO-220 ............................................................................................... 1
Changed symbols for Thermal Information ......................................................................................................................... 19
Changes from Revision H (April 2013) to Revision I Page
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5 Pin Configuration and Functions
DDPAK/TO-263 (KTT) Package DDPAK/TO-263 ( KTT) Package
3 Pins Side View
Top View
WSON (NGN) Package
8 Pins
Top View
TO-220 (NDE) Package
4 Pins
Front View
SOT-223 (DCY) Package
3 Pins
Front View Pin 2 and pin 7 are fused to center DAP
Pin 5 and 6 need to be tied together on
PCB board
Pin Functions
PIN I/O DESCRIPTION
NAME NDE KTT DCY NGN
IN 1 1 1 3 I Unregulated input voltage.
GND 2 2 2 2 Ground
Regulated output voltage. This pin requires an output capacitor to
OUT 3 3 3 5, 6 O maintain stability. See Detailed Design Procedure for output
capacitor details.
GND 4 4 4 7 Ground
N/C 1, 4, 8 No connection
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6 Specifications
6.1 Absolute Maximum Ratings(1)(2)
MIN MAX UNIT
LM2940-N KTT, NDE, DCY 100 ms 60 V
LM2940C KTT, NDE 1 ms 45
Internally
Internal power dissipation(3) Limited
Maximum junction temperature 150
TO-220 (NDE), Wave (10 s) 260
Soldering DDPAK/TO-263 (KTT) (30 s) 235
temperature(4) °C
SOT-223 (DCY) (30 s) 260
WSON-8 (NGN) (30 s) 235
Storage temperature, Tstg 65 150
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Recommended Operating Conditions are
conditions under which the device functions but the specifications might not be ensured. For ensured specifications and test conditions
see the Electrical Characteristics (5 V and 8 V).
(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 is a function of the maximum junction temperature, TJ, the junction-to-ambient thermal
resistance, RθJA, and the ambient temperature, TA. Exceeding the maximum allowable power dissipation will cause excessive die
temperature, and the regulator will go into thermal shutdown. The value of R θJA (for devices in still air with no heatsink) is 23.3°C/W for
the TO-220 package, 40.9°C/W for the DDPAK/TO-263 package, and 59.3°C/W for the SOT-223 package. The effective value of RθJA
can be reduced by using a heatsink (see Heatsinking for specific information on heatsinking). The value of RθJA for the WSON package
is specifically dependent on PCB trace area, trace material, and the number of layers and thermal vias. For improved thermal resistance
and power dissipation for the WSON package, refer to Application Note AN-1187 Leadless Leadframe Package (LLP) (SNOA401). It is
recommended that 6 vias be placed under the center pad to improve thermal performance.
(4) Refer to JEDEC J-STD-020C for surface mount device (SMD) package reflow profiles and conditions. Unless otherwise stated, the
temperature and time are for Sn-Pb (STD) only.
6.2 ESD Ratings VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) MIN MAX UNIT
Input voltage 6 26 V
LM2940-N NDE, LM2940-N KTT 40 125
LM2940C NDE, LM2940C KTT 0 125
Temperature °C
LM2940-N DCY 40 85
LM2940-N NGN 40 125
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6.4 Thermal Information LM2940-N, LM2940C LM2940-N
TO-220 DDPAK/TO-263 SOT-223 WSON
THERMAL METRIC(1) UNIT
(NDE) (KTT) (DCY) (NGN)
3 PINS 3 PINS 4 PINS 8 PINS
RθJA Junction-to-ambient thermal resistance(2) 23.3 40.9 59.3 40.5
RθJC(top) Junction-to-case (top) thermal resistance 16.1 43.5 38.9 26.2
RθJB Junction-to-board thermal resistance 4.8 23.5 8.1 17.0 °C/W
ψJT Junction-to-top characterization parameter 2.7 10.3 1.7 0.2
ψJB Junction-to-board characterization parameter 4.8 22.5 8.0 17.2
RθJC(bot) Junction-to-case (bottom) thermal resistance 1.1 0.8 n/a 3.2
(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 package vertically mounted with a heat sink in the middle of a PCB which is
compliant to the JEDEC HIGH-K 2s2p (JESD51-7). The heatsink-to-ambient thermal resistance, RƟSA, is 21.7°C/W. See Heatsinking
TO-220 Package Parts for more information.
6.5 Electrical Characteristics (5 V and 8 V)
Unless otherwise specified: VIN = VOUT + 5 V, IOUT = 1 A and COUT = 22 µF. MIN (minimum) and MAX (maximum) limits apply
over the recommended operating temperature range, unless otherwise noted; typical limits apply for TA= TJ= 25°C.
5 V 8 V
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Input voltage 5 mA IOUT 1 A 6.25 26 9.4 26
5 mA IOUT 1A 4.75 5 5.25 7.6 8 8.4 V
Output voltage 5 mA IOUT 1A, TJ= 25°C 4.85 5 5.15 7.76 8 8.24
VOUT + 2 V VIN 26 V, IOUT = 5 mA
Line regulation 20 50 20 80 mV
TJ= 25°C
50 mA IOUT 1 A LM2940-N 35 80 55 130
Load regulation LM2940-N 35 50 55 80 mV
50 mA IOUT 1 A
TJ= 25°C LM2940C 35 50 55 80
Output 100 mADC, 20 mArms, ƒOUT = 120 Hz 35 55 mΩ
impedance VOUT + 2 V VIN 26 V, LM2940-N 10 20 10 20
IOUT = 5 mA
VOUT + 2 V VIN 26 V, LM2940-N 10 15 10 15
IOUT = 5 mA
Quiescent current LM2940C 10 15 mA
TJ= 25°C
VIN = VOUT + 5 V, IOUT = 1 A 30 60 30 60
VIN = VOUT + 5 V, IOUT = 1 A 30 45 30 45
TJ= 25°C
Output noise 10 Hz to 100 kHz, IOUT = 5 mA 150 240 µVrms
voltage ƒOUT = 120 Hz, 1 Vrms, IOUT = LM2940-N 54 72 48 66
100 mA
Ripple rejection dB
ƒOUT = 120 Hz, 1 Vrms, IOUT = LM2940-N 60 72 54 66
100 mA LM2940C 60 72 54 66
TJ= 25°C
Long-term mV/1000
20 32
stability Hr
IOUT = 1A 0.5 1 0.5 1 V
IOUT = 1A, TJ= 25°C 0.5 0.8 0.5 0.8
Dropout voltage IOUT = 100 mA 110 200 110 200 mV
IOUT = 100 mA, TJ= 25°C 110 150 110 150
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Electrical Characteristics (5 V and 8 V) (continued)
Unless otherwise specified: VIN = VOUT + 5 V, IOUT = 1 A and COUT = 22 µF. MIN (minimum) and MAX (maximum) limits apply
over the recommended operating temperature range, unless otherwise noted; typical limits apply for TA= TJ= 25°C.
5 V 8 V
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Short-circuit See(1), TJ= 25°C 1.6 1.9 1.6 1.9 A
current ROUT = 100Ω, T 100 ms LM2940-N 60 75 60 75
Maximum line V
ROUT = 100Ω, T 1 ms
transient LM2940C 45 55 45 555
TJ= 25°C
ROUT = 100 ΩLM2940-N –15 –30 –15 –30
Reverse polarity V
ROUT = 100 Ω
DC input voltage LM2940C –15 –30 –15 –30
TJ= 25°C
Reverse polarity ROUT = 100 Ω, T 100 ms LM2940-N –50 –75 –50 –75
Transient Input V
ROUT = 100 Ω, T 1 ms LM2940C –45 –55
Voltage
(1) Output current will decrease with increasing temperature but will not drop below 1 A at the maximum specified temperature.
6.6 Electrical Characteristics (9 V and 10 V)
Unless otherwise specified: VIN = VOUT + 5 V, IOUT = 1 A and COUT = 22 µF. MIN (minimum) and MAX (maximum) limits apply
over the recommended operating temperature range, unless otherwise noted; typical limits apply for TA= TJ= 25°C.
9 V 10 V
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Input voltage 5 mA IOUT 1 A 10.5 26 11.5 26
5 mA IOUT 1A 8.55 9 9.45 9.5 10 10.5 V
Output voltage 5 mA IOUT 1A, TJ= 25°C 8.73 9 9.27 9.7 10 10.3
VOUT + 2 V VIN 26 V, IOUT = 5 mA
Line regulation 20 90 20 100 mV
TJ= 25°C
50 mA IOUT 1 A LM2940-N 60 150 65 165
Load regulation 50 mA IOUT 1 A LM2940-N 60 90 65 100 mV
TJ= 25°C LM2940C 60 90
Output 100 mADC, 20 mArms, ƒOUT = 120 Hz 60 65 mΩ
impedance VOUT + 2 V VIN 26 V, LM2940-N 10 20 10 20
IOUT = 5 mA
VOUT + 2 V VIN 26 V, LM2940-N 10 15 15
IOUT = 5 mA
Quiescent current LM2940C 10 15 mA
TJ= 25°C
VIN = VOUT + 5 V, IOUT = 1 A 30 60 30 60
VIN = VOUT + 5 V, IOUT = 1 A 30 45 30 45
TJ= 25°C
Output noise 10 Hz to 100 kHz, IOUT = 5 mA 270 300 µVrms
voltage ƒOUT = 120 Hz, 1 Vrms LM2940-N 46 64 45 63
IOUT = 100 mA
Ripple rejection dB
ƒOUT = 120 Hz, 1 Vrms LM2940-N 52 64 51 63
IOUT = 100 mA LM2940C 52 64
TJ= 25°C
Long-term mV/1000
34 36
stability Hr
IOUT = 1A 0.5 1 0.5 1 V
IOUT = 1A, TJ= 25°C 0.5 0.8 0.5 0.8
Dropout voltage IOUT = 100 mA 110 200 110 200 mV
IOUT = 100 mA, TJ= 25°C 110 150 110 150
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Electrical Characteristics (9 V and 10 V) (continued)
Unless otherwise specified: VIN = VOUT + 5 V, IOUT = 1 A and COUT = 22 µF. MIN (minimum) and MAX (maximum) limits apply
over the recommended operating temperature range, unless otherwise noted; typical limits apply for TA= TJ= 25°C.
9 V 10 V
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Short-circuit See(1), TJ= 25°C 1.6 1.9 1.6 1.9 A
current ROUT = 100Ω, T 100 ms LM2940-N 60 75 60 75
Maximum line V
ROUT = 100Ω, T 100 ms
transient LM2940C 45 55
TJ= 25°C
ROUT = 100 ΩLM2940-N –15 –30 –15 –30
Reverse polarity V
ROUT = 100 Ω–15 –30
DC input voltage LM2940C
TJ= 25°C
Reverse polarity LM2940-N –50 –75 –50 –75
Transient Input ROUT = 100 Ω, T 100 ms V
LM2940C –45 –55
Voltage
(1) Output current will decrease with increasing temperature but will not drop below 1 A at the maximum specified temperature.
6.7 Electrical Characteristics (12 V and 15 V)
Unless otherwise specified: VIN = VOUT + 5 V, IOUT = 1 A and COUT = 22 µF. MIN (minimum) and MAX (maximum) limits apply
over the recommended operating temperature range, unless otherwise noted; typical limits apply for TA= TJ= 25°C.
12 V 15 V
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Input voltage 5 mA IOUT 1 A 13.6 26 16.75 26
5 mA IOUT 1A 11.40 12 12.6 14.25 15 15.75 V
Output voltage 5 mA IOUT 1A, TJ= 25°C 11.64 12 12.36 14.55 15 15.45
VOUT + 2 V VIN 26 V, IOUT = 5 mA
Line regulation 20 120 20 150 mV
TJ= 25°C
50 mA IOUT 1 A LM2940-N 55 200
Load regulation 50 mA IOUT 1 A LM2940-N 55 120 mV
TJ= 25°C LM2940C 55 120 70 150
Output 100 mADC, 20 mArms, ƒOUT = 120 Hz 80 100 mΩ
impedance VOUT + 2 V VIN 26 V, LM2940-N 10 20
IOUT = 5 mA
VOUT + 2 V VIN 26 V, LM2940-N 10 15
IOUT = 5 mA
Quiescent current LM2940C 10 15 10 15 mA
TJ= 25°C
VIN = VOUT + 5 V, IOUT = 1 A 30 60 30 60
VIN = VOUT + 5 V, IOUT = 1 A 30 45 30 45
TJ= 25°C
Output noise 10 Hz to 100 kHz, IOUT = 5 mA 360 450 µVrms
voltage ƒOUT = 120 Hz, 1 Vrms, IOUT = LM2940-N 48 66
100 mA
Ripple rejection dB
ƒOUT = 120 Hz, 1 Vrms, IOUT = LM2940-N 54 66
100 mA LM2940C 54 66 52 64
TJ= 25°C
Long-term mV/1000
48 60
stability Hr
IOUT = 1A 0.5 1 0.5 1 V
IOUT = 1A, TJ= 25°C 0.5 0.8 0.5 0.8
Dropout voltage IOUT = 100 mA 110 200 110 200 mV
IOUT = 100 mA, TJ= 25°C 110 150 110 150
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Electrical Characteristics (12 V and 15 V) (continued)
Unless otherwise specified: VIN = VOUT + 5 V, IOUT = 1 A and COUT = 22 µF. MIN (minimum) and MAX (maximum) limits apply
over the recommended operating temperature range, unless otherwise noted; typical limits apply for TA= TJ= 25°C.
12 V 15 V
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Short-circuit See(1), TJ= 25°C 1.6 1.9 1.6 1.9 A
current ROUT = 100Ω, T 100 ms LM2940-N 60 75
Maximum line V
ROUT = 100Ω, T 100 ms
transient LM2940C 45 55 45 55
TJ= 25°C
ROUT = 100 ΩLM2940-N –15 –30
Reverse polarity V
ROUT = 100 Ω
DC input voltage LM2940C –15 –30 –15 –30
TJ= 25°C
Reverse polarity ROUT = 100 Ω, T 100 ms LM2940-N –50 –75
transient input V
–45 –55 –45 –55
ROUT = 100 Ω, T 1 ms LM2940C
voltage
(1) Output current will decrease with increasing temperature but will not drop below 1 A at the maximum specified temperature.
6.8 Typical Characteristics
Figure 2. Dropout Voltage vs. Temperature
Figure 1. Dropout Voltage
Figure 3. Output Voltage vs. Temperature Figure 4. Quiescent Current vs. Temperature
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Typical Characteristics (continued)
Figure 5. Quiescent Current Figure 6. Quiescent Current
Figure 8. Load Transient Response
Figure 7. Line Transient Response
Figure 10. Low Voltage Behavior
Figure 9. Ripple Rejection
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Typical Characteristics (continued)
Figure 11. Low Voltage Behavior Figure 12. Low Voltage Behavior
Figure 14. Low Voltage Behavior
Figure 13. Low Voltage Behavior
Figure 16. Output at Voltage Extremes
Figure 15. Output at Voltage Extremes
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Typical Characteristics (continued)
Figure 17. Output at Voltage Extremes Figure 18. Output at Voltage Extremes
Figure 19. Output at Voltage Extremes Figure 20. Output Capacitor ESR
Figure 21. Peak Output Current Figure 22. Output Impedance
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Typical Characteristics (continued)
Figure 24. Maximum Power Dissipation (SOT-223)
Figure 23. Maximum Power Dissipation (TO-220)
Figure 25. Maximum Power Dissipation (DDPAK/TO-263)
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7 Detailed Description
7.1 Overview
The LM2940 positive voltage regulator features the ability to source 1 A of output current with a dropout voltage
of typically 0.5 V and a maximum of 1 V over the entire temperature range. Furthermore, a quiescent current
reduction circuit has been included which reduces the ground current when the differential between the input
voltage and the output voltage exceeds approximately 3 V. The quiescent current with 1 A of output current and
an input-output differential of 5 V is therefore only 30 mA. Higher quiescent currents only exist when the regulator
is in the dropout mode (VIN VOUT 3 V).
7.2 Functional Block Diagram
7.3 Feature Description
7.3.1 Short-Circuit Current Limit
The internal current limit circuit is used to protect the LDO against high-load current faults or shorting events. The
LDO is not designed to operate in a steady-state current limit. During a current-limit event, the LDO sources
constant current. Therefore, the output voltage falls when load impedance decreases. Note, also, that if a current
limit occurs and the resulting output voltage is low, excessive power may be dissipated across the LDO, resulting
a thermal shutdown of the output.
7.3.2 Overvoltage Shutdown (OVSD)
Input voltage greater than typically 30 V will cause the LM2940 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.
7.3.3 Thermal Shutdown (TSD)
The LM2940 contains the thermal shutdown circuitry to turn off the output when excessive heat is dissipated in
the LDO. The internal protection circuitry of the LM2940 is designed to protect against thermal overload
conditions. The TSD circuitry is not intended to replace proper heat sinking. Continuously running the device into
thermal shutdown degrades its reliability as the junction temperature will be exceeding the absolute maximum
junction temperature rating.
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7.4 Device Functional Modes
7.4.1 Operation with Enable Control
The LM2940 design does not include any undervoltage lockout (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 + 1 V, the LM2940 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
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The LM2940-N and LM2940C positive voltage regulators feature the ability to source 1 A of output current with a
dropout voltage of typically 0.5 V and a maximum of 1 V over the entire temperature range. The output capacitor,
COUT, must have a capacitance value of at least 22 µF with an ESR of at least 100 mΩ, but no more than 1 Ω.
The minimum capacitance value and the ESR requirements apply across the entire expected operating ambient
temperature range.
8.2 Typical Application
*Required if regulator is located far from power supply filter.
**COUT must be at least 22 μF to maintain stability. May be increased without bound to maintain regulation during
transients. Locate as close as possible to the regulator. This capacitor must be rated over the same operating
temperature range as the regulator and the ESR is critical; see curve.
Figure 26. Typical Application
8.2.1 Design Requirements
Table 1. Design Parameters
DESIGN PARAMETER EXAMPLE VALUE
Input voltage range 6 V to 26 V
Output voltage range 8 V
Output current range 5 mA to 1 A
Input capacitor value 0.47 µF
Output capacitor value 22 µF minimum
Output capacitor ESR range 100 mΩto 1 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.
8.2.2.1.1 Minimum Capacitance
The minimum output capacitance required to maintain stability is 22 μF (this value may be increased without
limit). Larger values of output capacitance will give improved transient response.
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Product Folder Links: LM2940-N LM2940C
LM2940-N
,
LM2940C
SNVS769J MARCH 2000REVISED DECEMBER 2014
www.ti.com
8.2.2.1.2 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.
Figure 27. Output Capacitor 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.
8.2.3 Application Curves
Figure 29. Output at Voltage Extremes
Figure 28. Low Voltage Behavior
16 Submit Documentation Feedback Copyright © 2000–2014, Texas Instruments Incorporated
Product Folder Links: LM2940-N LM2940C
1
2
3
Ground
CIN COUT
VOUT
VIN
4
COUT
VIN
VOUT
CIN
Ground
GND
5
6
1
2
4
7
8
3
LM2940-N
,
LM2940C
www.ti.com
SNVS769J MARCH 2000REVISED DECEMBER 2014
9 Power Supply Recommendations
The device is designed to operate from an input voltage supply range between VOUT + 1 V up to a maximum of
26 V. This input supply must be well regulated and free of spurious noise. To ensure that the LM2940 output
voltage is well regulated, the input supply should be at least VOUT + 2 V.
10 Layout
10.1 Layout Guidelines
The dynamic performance of the LM2940 is dependent on the layout of the PCB. PCB layout practices that are
adequate for typical LDOs may degrade the PSRR, noise, or transient performance of the LM2940. Best
performance is achieved by placing CIN and COUT on the same side of the PCB as the LM2940, and as close as
is practical to the package. The ground connections for CIN and COUT should be back to the LM2940 ground pin
using as wide and short of a copper trace as is practical.
10.2 Layout Examples
Figure 30. LM2940 WSON Layout
Figure 31. LM2940 SOT-223 Layout
Figure 32. TO-263 Layout
Copyright © 2000–2014, Texas Instruments Incorporated Submit Documentation Feedback 17
Product Folder Links: LM2940-N LM2940C
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,
LM2940C
SNVS769J MARCH 2000REVISED DECEMBER 2014
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10.3 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(1)(2).
To determine if a heatsink is required, the power dissipated by the regulator, PD, must be calculated.
Figure 33 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 33. 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)
where
TJ(MAX) is the maximum allowable junction temperature, which is 125°C for commercial grade parts.
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
If the maximum allowable value for RθJA is found to be 23.3°C/W for the TO-220
package (with a heatsink of 21.7°C/W RθSA), 40.9°C/W for the DDPAK/TO-263 package,
or 59.3°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 RθJA falls below these limits, a heatsink is required.
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Recommended Operating Conditions are
conditions under which the device functions but the specifications might not be ensured. For ensured specifications and test conditions
see the Electrical Characteristics (5 V and 8 V).
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and
specifications.
18 Submit Documentation Feedback Copyright © 2000–2014, Texas Instruments Incorporated
Product Folder Links: LM2940-N LM2940C
LM2940-N
,
LM2940C
www.ti.com
SNVS769J MARCH 2000REVISED DECEMBER 2014
Heatsinking (continued)
10.3.1 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 manufactured heatsink is to be selected, the value of heatsink-to-ambient thermal resistance, RθSA, must first
be calculated:
RθSA = RθJA RθCS 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.
RθCS is defined as the thermal resistance between the case and the surface of the heatsink. The value of RθCS
will vary from about 0.5°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 RθCS. (3)
When a value for RθSA is found using Equation 3,a heatsink must be selected that has a value that is less than
or equal to this number.
RθSA 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.
Copyright © 2000–2014, Texas Instruments Incorporated Submit Documentation Feedback 19
Product Folder Links: LM2940-N LM2940C
LM2940-N
,
LM2940C
SNVS769J MARCH 2000REVISED DECEMBER 2014
www.ti.com
11 Device and Documentation Support
11.1 Documentation Support
11.1.1 Related Documentation
For related documentation see the following:
Application Note AN-1028 Maximum Power Enhancement Techniques for Power Packages (SNVA036).
Application Note AN-1187 Leadless Leadframe Package (LLP) (SNOA401).
11.2 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.
Table 2. Related Links
TECHNICAL TOOLS & SUPPORT &
PARTS PRODUCT FOLDER SAMPLE & BUY DOCUMENTS SOFTWARE COMMUNITY
LM2940-N Click here Click here Click here Click here Click here
LM2940C Click here Click here Click here Click here Click here
11.3 Trademarks
All trademarks are the property of their respective owners.
11.4 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.
11.5 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.
20 Submit Documentation Feedback Copyright © 2000–2014, Texas Instruments Incorporated
Product Folder Links: LM2940-N LM2940C
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2021
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead finish/
Ball material
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2940CS-12 NRND DDPAK/
TO-263 KTT 3 45 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CS
-12 P+
LM2940CS-12/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-12 P+
LM2940CS-15 NRND DDPAK/
TO-263 KTT 3 45 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CS
-15 P+
LM2940CS-15/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-15 P+
LM2940CS-5.0 NRND DDPAK/
TO-263 KTT 3 45 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CS
-5.0 P+
LM2940CS-5.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-5.0 P+
LM2940CS-9.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-9.0 P+
LM2940CSX-12 NRND DDPAK/
TO-263 KTT 3 500 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CS
-12 P+
LM2940CSX-12/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-12 P+
LM2940CSX-15/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-15 P+
LM2940CSX-5.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-5.0 P+
LM2940CSX-9.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR 0 to 125 LM2940CS
-9.0 P+
LM2940CT-12 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CT
-12 P+
LM2940CT-12/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM 0 to 125 LM2940CT
-12 P+
LM2940CT-15 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CT
-15 P+
LM2940CT-15/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM 0 to 125 LM2940CT
-15 P+
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2021
Addendum-Page 2
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead finish/
Ball material
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2940CT-5.0 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI 0 to 125 LM2940CT
-5.0 P+
LM2940CT-5.0/LF01 ACTIVE TO-220 NDG 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR LM2940CT
-5.0 P+
LM2940CT-5.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM 0 to 125 LM2940CT
-5.0 P+
LM2940CT-9.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM 0 to 125 LM2940CT
-9.0 P+
LM2940IMP-10/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L55B
LM2940IMP-12/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L56B
LM2940IMP-15 NRND SOT-223 DCY 4 1000 Non-RoHS
& Green Call TI Call TI -40 to 85 L70B
LM2940IMP-15/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L70B
LM2940IMP-5.0 NRND SOT-223 DCY 4 1000 Non-RoHS
& Green Call TI Call TI -40 to 85 L53B
LM2940IMP-5.0/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L53B
LM2940IMP-9.0/NOPB ACTIVE SOT-223 DCY 4 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L0EB
LM2940IMPX-10/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L55B
LM2940IMPX-12/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L56B
LM2940IMPX-5.0/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L53B
LM2940IMPX-8.0/NOPB ACTIVE SOT-223 DCY 4 2000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L54B
LM2940LD-12 NRND WSON NGN 8 1000 Non-RoHS
& Green Call TI Call TI -40 to 125 L00018B
LM2940LD-12/NOPB ACTIVE WSON NGN 8 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 125 L00018B
LM2940LD-5.0/NOPB ACTIVE WSON NGN 8 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 125 L00014B
LM2940S-10 NRND DDPAK/
TO-263 KTT 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940S
-10 P+
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2021
Addendum-Page 3
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead finish/
Ball material
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2940S-10/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-10 P+
LM2940S-12 NRND DDPAK/
TO-263 KTT 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940S
-12 P+
LM2940S-12/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-12 P+
LM2940S-5.0 NRND DDPAK/
TO-263 KTT 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940S
-5.0 P+
LM2940S-5.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-5.0 P+
LM2940S-8.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-8.0 P+
LM2940S-9.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 45 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-9.0 P+
LM2940SX-10 NRND DDPAK/
TO-263 KTT 3 500 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940S
-10 P+
LM2940SX-10/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-10 P+
LM2940SX-12 NRND DDPAK/
TO-263 KTT 3 500 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940S
-12 P+
LM2940SX-12/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-12 P+
LM2940SX-5.0 NRND DDPAK/
TO-263 KTT 3 500 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940S
-5.0 P+
LM2940SX-5.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-5.0 P+
LM2940SX-8.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-8.0 P+
LM2940SX-9.0/NOPB ACTIVE DDPAK/
TO-263 KTT 3 500 RoHS-Exempt
& Green SN Level-3-245C-168 HR -40 to 125 LM2940S
-9.0 P+
LM2940T-10.0 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940T
10.0 P+
LM2940T-10.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2940T
10.0 P+
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2021
Addendum-Page 4
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead finish/
Ball material
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2940T-12.0 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940T
12.0 P+
LM2940T-12.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2940T
12.0 P+
LM2940T-5.0 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940T
-5.0 P+
LM2940T-5.0/LF08 ACTIVE TO-220 NEB 3 45 RoHS & Green SN Level-3-245C-168 HR LM2940T
-5.0 P+
LM2940T-5.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2940T
-5.0 P+
LM2940T-8.0 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940T
-8.0 P+
LM2940T-8.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2940T
-8.0 P+
LM2940T-9.0 NRND TO-220 NDE 3 45 Non-RoHS
& Green Call TI Call TI -40 to 125 LM2940T
-9.0 P+
LM2940T-9.0/NOPB ACTIVE TO-220 NDE 3 45 RoHS & Green SN Level-1-NA-UNLIM -40 to 125 LM2940T
-9.0 P+
(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.
(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.
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2021
Addendum-Page 5
(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.
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM2940CSX-12 DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940CSX-12/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940CSX-15/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940CSX-5.0/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940CSX-9.0/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940IMP-10/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMP-12/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMP-15 SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMP-15/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMP-5.0 SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMP-5.0/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMP-9.0/NOPB SOT-223 DCY 4 1000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMPX-10/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMPX-12/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
PACKAGE MATERIALS INFORMATION
www.ti.com 29-Sep-2019
Pack Materials-Page 1
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM2940IMPX-5.0/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940IMPX-8.0/NOPB SOT-223 DCY 4 2000 330.0 16.4 7.0 7.5 2.2 12.0 16.0 Q3
LM2940LD-12 WSON NGN 8 1000 178.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1
LM2940LD-12/NOPB WSON NGN 8 1000 178.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1
LM2940LD-5.0/NOPB WSON NGN 8 1000 178.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1
LM2940SX-10 DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-10/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-12 DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-12/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-5.0 DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-5.0/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-8.0/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2940SX-9.0/NOPB DDPAK/
TO-263 KTT 3 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 29-Sep-2019
Pack Materials-Page 2
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM2940CSX-12 DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940CSX-12/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940CSX-15/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940CSX-5.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940CSX-9.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940IMP-10/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMP-12/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMP-15 SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMP-15/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMP-5.0 SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMP-5.0/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMP-9.0/NOPB SOT-223 DCY 4 1000 367.0 367.0 35.0
LM2940IMPX-10/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2940IMPX-12/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2940IMPX-5.0/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2940IMPX-8.0/NOPB SOT-223 DCY 4 2000 367.0 367.0 35.0
LM2940LD-12 WSON NGN 8 1000 210.0 185.0 35.0
LM2940LD-12/NOPB WSON NGN 8 1000 210.0 185.0 35.0
LM2940LD-5.0/NOPB WSON NGN 8 1000 210.0 185.0 35.0
LM2940SX-10 DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-10/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-12 DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-12/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-5.0 DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-5.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-8.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
LM2940SX-9.0/NOPB DDPAK/TO-263 KTT 3 500 367.0 367.0 45.0
PACKAGE MATERIALS INFORMATION
www.ti.com 29-Sep-2019
Pack Materials-Page 3
MECHANICAL DATA
NDE0003B
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MECHANICAL DATA
KTT0003B
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BOTTOM SIDE OF PACKAGE
TS3B (Rev F)
MECHANICAL DATA
MPDS094A – APRIL 2001 – REVISED JUNE 2002
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
DCY (R-PDSO-G4) PLASTIC SMALL-OUTLINE
4202506/B 06/2002
6,30 (0.248)
6,70 (0.264)
2,90 (0.114)
3,10 (0.122)
6,70 (0.264)
7,30 (0.287) 3,70 (0.146)
3,30 (0.130)
0,02 (0.0008)
0,10 (0.0040)
1,50 (0.059)
1,70 (0.067)
0,23 (0.009)
0,35 (0.014)
1 2 3
4
0,66 (0.026)
0,84 (0.033)
1,80 (0.071) MAX
Seating Plane
0°–10°
Gauge Plane
0,75 (0.030) MIN
0,25 (0.010)
0,08 (0.003)
0,10 (0.004) M
2,30 (0.091)
4,60 (0.181) M
0,10 (0.004)
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.
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PACKAGE OUTLINE
C
8X 0.35
0.25
2X
2.4
0.8 MAX
(0.25)
(0.25) (0.2)
(0.15)
0.05
0.00
8X 0.6
0.4
3 0.05
2.2 0.05
6X 0.8
A4.1
3.9 B
4.1
3.9
(0.2) TYP
WSON - 0.8 mm max heightNGN0008A
PLASTIC SMALL OUTLINE - NO LEAD
4214794/A 11/2019
PIN 1 INDEX AREA
SEATING PLANE
0.08 C
1
45
8
PIN 1 ID 0.1 C A B
0.05 C
THERMAL PAD
EXPOSED SYMM
SYMM
9
DETAIL A
SEE
NOTES:
1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing
per ASME Y14.5M.
2. This drawing is subject to change without notice.
3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.
SCALE 3.000
PIN 1 ID DETAIL A
PIN 1 ID
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EXAMPLE BOARD LAYOUT
0.07 MIN
ALL AROUND
0.07 MAX
ALL AROUND
8X (0.3)
(3)
(3.3)
6X (0.8)
(2.2)
( 0.2) VIA
TYP (0.85)
(1.25)
8X (0.5)
(R0.05) TYP
WSON - 0.8 mm max heightNGN0008A
PLASTIC SMALL OUTLINE - NO LEAD
4214794/A 11/2019
SYMM
1
45
8
LAND PATTERN EXAMPLE
EXPOSED METAL SHOWN
SCALE:15X
SYMM 9
NOTES: (continued)
4. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature
number SLUA271 (www.ti.com/lit/slua271).
5. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown
on this view. It is recommended that vias under paste be filled, plugged or tented.
SOLDER MASK
OPENING
SOLDER MASK
METAL UNDER
SOLDER MASK
DEFINED
EXPOSED
METAL
METAL
SOLDER MASK
OPENING
SOLDER MASK DETAILS
NON SOLDER MASK
DEFINED
(PREFERRED)
EXPOSED
METAL
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EXAMPLE STENCIL DESIGN
(R0.05) TYP
0.59
4X (1.31)
8X (0.3)
8X (0.5)
4X (0.98)
(3.3)
(0.755)
6X (0.8)
WSON - 0.8 mm max heightNGN0008A
PLASTIC SMALL OUTLINE - NO LEAD
4214794/A 11/2019
NOTES: (continued)
6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate
design recommendations.
SOLDER PASTE EXAMPLE
BASED ON 0.125 mm THICK STENCIL
EXPOSED PAD 9:
78% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE
SCALE:20X
SYMM
1
45
8
METAL
TYP
SYMM 9
MECHANICAL DATA
NDG0003F
www.ti.com
T03F (Rev B)
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