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2024-11-22 926

The LM340 is a reliable power regulator designed to provide a stable 1.5-ampere output across various applications. It operates efficiently within voltage ranges of 5V to 24V, featuring thermal overload protection to prevent overheating and ensure durability. Widely used in consumer electronics and industrial systems, it plays a role in managing voltage levels for devices like microcontrollers and communication equipment. Its dependable performance and precision make it great in sensitive electronic environments, emphasizing the importance of careful component selection and thorough pre-use testing for optimal circuit design.

Catalog

LM340 Pinout Configuration

Pin Name	Pin NO.	I/O	Description
INPUT	1	I	Input voltage pin
GND	2	I/O	Ground pin
OUTPUT	3	O	Output voltage pin

CAD Model for LM340

LM340 Overview

The LM340 is a dependable three-terminal positive voltage regulator designed for stable performance, featuring built-in protections like current limiting, thermal shutdown, and safe-area compensation for enhanced safety and durability. It efficiently handles heat, delivering consistent output currents up to 1.5 amperes. Current limiting safeguards the regulator and connected components from damage due to excessive current, ensuring system stability, while thermal shutdown prevents overheating by automatically deactivating the regulator in high-temperature conditions, extending its lifespan. Safe-area compensation maintains efficiency by keeping load conditions within safe operational limits, reducing wear and the need for maintenance. Employing heat sinks or cooling methods can further boost the LM340’s performance, preventing overheating and sustaining efficiency, making it a reliable choice for long-term use in various applications.

Technical Specifications

Detailed specification of the Texas Instruments LM340T-15.

Type	Parameter
Lifecycle Status	NRND (Last Updated: 2 days ago)
Mount	Through Hole
Mounting Type	Through Hole
Package / Case	TO-220-3
Number of Pins	3
Weight	2.299997 g
Operating Temperature	0°C ~ 125°C
Packaging	Tube
JESD-609 Code	e0
Part Status	Not For New Designs
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	3
Termination	Through Hole
ECCN Code	EAR99
Terminal Finish	Tin/Lead (Sn/Pb)
Terminal Position	SINGLE
Peak Reflow Temperature (°C)	NOT SPECIFIED
Number of Functions	1
Terminal Pitch	2.54 mm
REACH Compliance Code	not_compliant
Current Rating	1 A
Time @ Peak Reflow Temperature (Max)	NOT SPECIFIED
Base Part Number	LM340
Pin Count	3
Number of Outputs	1
Qualification Status	Not Qualified
Voltage - Input (Max)	35 V
Output Voltage	15 V
Output Type	Fixed
Max Output Current	1 A
Voltage	15 V
Max Supply Voltage	30 V
Min Supply Voltage	17.5 V
Output Configuration	Positive
Quiescent Current	8 mA
Accuracy	±2%
Max Output Voltage	15 V
Output Voltage 1	15 V
Number of Regulators	1
Min Input Voltage	17.7 V
Protection Features	Over Temperature, Short Circuit
Voltage Dropout (Max)	2 V @ 1 A
PSRR	80 dB (120 Hz)
Dropout Voltage	2.9 V
Dropout Voltage 1 (Nominal)	2 V
Power Supply Rejection Ratio (PSRR)	80 dB
Nominal Output Voltage	15 V
Output Voltage Accuracy	±2%
Height	4.7 mm
Length	14.986 mm
Width	10.16 mm
Thickness	4.572 mm
REACH SVHC	No SVHC
RoHS Status	Non-RoHS Compliant
Lead Free	Contains Lead

Characteristics of LM340

• Output Current up to 1.5 A - Delivers a reliable current supply for powering a wide range of devices and circuits.

• Available in Fixed 5-V, 12-V, and 15-V Options - Offers flexibility in voltage selection to match specific application requirements.

• Output Voltage Tolerances of ±2% at TJ = 25°C (LM340A) - Ensures precise voltage regulation, maintaining consistent performance under standard conditions.

• Line Regulation of 0.01%/V at 1-A Load (LM340A) - Provides minimal output variation with changes in input voltage, ensuring stable operation.

• Load Regulation of 0.3%/A (LM340A) - Maintains steady output voltage even with varying load currents, improving reliability.

• Internal Thermal Overload, Short-Circuit, and SOA Protection - Protects the regulator and connected components from overheating, overcurrent, and unsafe operating conditions.

• Available in Space-Saving SOT-223 Package - Compact design enables efficient use of PCB space in tight layouts.

• Output Capacitance Not Required for Stability - Simplifies circuit design by removing the need for external capacitors to maintain stability.

LM340 Block Diagram

Applications of LM340

• Industrial Power Supplies - Provides stable voltage regulation for reliable operation in industrial systems, ensuring consistent performance under varying loads.

• SMPS Post Regulation - Used to smooth and stabilize the output of switching power supplies, improving voltage accuracy and reducing noise.

• HVAC Systems - Regulates power in heating, ventilation, and air conditioning systems for efficient and consistent performance.

• AC Inverters - Ensures stable voltage regulation in AC inverter circuits, enhancing power delivery and system reliability.

• Test and Measurement Equipment - Maintains precise voltage levels to ensure accuracy and reliability in sensitive measurement tools and testing devices.

• Brushed and Brushless DC Motor Drivers - Provides regulated power to motor drivers, supporting smooth operation and improved motor control.

• Solar Energy String Inverters - Stabilizes power in solar inverters, ensuring efficient energy conversion and system reliability in renewable energy setups.

Adjusting Output Voltage with the LM340

This straightforward circuit utilizes the LM340 to achieve a variable output voltage, guided by the following formula:

Boosting the LM340's Current Capacity

This configuration supports regulated outputs up to 5A. Q1 remains inactive at lower current levels and activates only when the current surpasses 600mA.

Similar Parts with Comparable Specifications

The three listed on the right share comparable specifications with the Texas Instruments LM340T-15.

Part Number

Manufacturer

Package / Case

Number of Pins

Number of Outputs

Max Output Current

Min Input Voltage

Voltage - Input (Max)

Nominal Output Voltage

Output Voltage

Max Output Voltage

Accuracy

Dropout Voltage

LM340T-15

Texas Instruments

TO-220-3

3

1

1 A

17.7 V

35 V

15 V

15 V

15 V

2 %

2.9 V

LM2940CT-12

Texas Instruments

TO-220-3

3

1

1 A

14.6 V

35 V

12 V

12 V

12 V

2 %

2 V

LM340T-12

Texas Instruments

TO-220-3

3

1

1 A

13.6 V

26 V

12 V

12 V

12 V

-

500 mV

LM340T-5.0

Texas Instruments

TO-220

3

1

1 A

7.5 V

-

5 V

-

5 V

2 %

2.5 V

Dimensions of the LM340 Regulator

Manufacturer Details

Texas Instruments, founded in 1958, leads in creating technology for electronics like cars and industrial machines. They employ over 30,000 people worldwide, working on new technologies that make devices more efficient and reliable. Their work improves how factories operate and helps products last longer and work better. Texas Instruments keeps innovating to stay ahead in the technology field, making them a big player in the industry.