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Texas Instruments LM1084IS-5.0/NOPB: Datasheet, Features,Applications,Advantages

Update time : 2025-11-25 13:45:57

The LM1084IS-5.0 is a fixed 5V low-dropout voltage regulator capable of delivering up to 5A of current with a dropout voltage of only 1.5V. Housed in a compact TO-263 package, it is highly suitable for high-current, space-constrained applications such as industrial power supplies, embedded systems, and consumer devices. This article explores its characteristics, specifications, internal structure, applications, and viable alternatives, providing a comprehensive guide for those seeking a stable 5V voltage regulation solution.

LM1084IS-5.0 Overview

The LM1084IS-5.0 is a 5A low-dropout positive voltage regulator launched by Texas Instruments, belonging to the LM1084 series. This device adopts the TO-263 (KTT package) and features stable and reliable performance, capable of operating normally within a wide temperature range (-40°C to 125°C). It has a fixed output voltage of 5.0V and integrates adjustment resistors, eliminating the need for external additional resistors to set the output voltage, thus simplifying circuit design.
The LM1084IS-5.0 includes a zener-adjusted bandgap reference, current limiting, and thermal shutdown circuits internally. This enables it to maintain a stable output under various operating conditions and possess a certain degree of self-protection capability. Compared with the LM1085 (3A version) and LM1086 (1.5A version) in the same series, the LM1084IS-5.0 is suitable for scenarios requiring larger output currents.

LM1084IS-5.0 Pinouts

Pin Number	Pin Name	Description
1	Input (Vin)	Connects to the input power supply, providing the operating voltage for the regulator.
2	Output (Vout)	Outputs the stable 5.0V voltage to power the load circuit. The package heatsink is electrically connected to this pin, aiding in heat dissipation and current handling.
3	Ground (GND)	Serves as the ground reference for the fixed output voltage version (LM1084IS-5.0). For adjustable versions, this pin functions as the adjustment pin (Adj) for setting output voltage via external resistors.

LM1084IS-5.0 Functional Diagram

The LM1084IS-5.0 functional diagram centers on a feedback - control system. The band - gap reference generates a stable 1.24V voltage. An operational amplifier compares this reference with the feedback from the output. The input supplies power, and a current source helps stabilize biasing. Transistors form a Darlington pair to boost current - driving capability. The substrate connects to ground. This setup regulates the output: any output deviation is corrected by the op - amp adjusting transistor conduction, ensuring a steady 5V output. For LM1084IS - 5.0, it simplifies to fixed 5V regulation, leveraging this core feedback - based architecture for stable, high - current 5V power delivery.

LM1084IS-5.0 Application Circuit

The LM1084IS-5.0 application circuit shown uses an adjustable configuration. The device has pins IN (input), OUT (output, labeled as CJT here likely a typo), and ADJ (adjust). C1 (10μF) filters input noise, especially needed if the device is far from main filters. R1 (121Ω) and R2 (5kΩ) form a voltage-divider feedback network. The formula VOUT=1.25V(1+R1/R2) sets output voltage by adjusting R2. A 10μF tantalum capacitor at the output stabilizes the voltage. This circuit leverages LM1084IS-5.0’s low - dropout, high - current capability, enabling flexible voltage regulation for applications like industrial power supplies or embedded systems needing stable, adjustable 5V - derived voltages (though adjustable here, the core 5A, 5V - fixed variant shares compatible design principles).

LM1084IS-5.0 Simplified Schematic

The LM1084IS-5.0 simplified schematic depicts a low-dropout linear regulator (LDO) engineered to deliver a stable 5.0V output at up to 5A. Core functional blocks include:
Precision Reference: A zener-trimmed bandgap reference generates a stable voltage benchmark, critical for output accuracy. This reference voltage is compared against a feedback signal to regulate Vₒᵤₜ.
Error Amplification: An operational amplifier (op-amp) compares the bandgap reference to a feedback voltage (derived from internal resistors for fixed 5V output, or via the ADJ pin for adjustable variants). The amplified error signal drives the power stage to correct output deviations.
Power Stage: Transistors form a high-current output stage, adjusting conduction to maintain Vₒᵤₜ stability despite input voltage fluctuations or load changes. This stage handles up to 5A while minimizing dropout voltage.
Protection Circuits: Integrated safeguards include thermal limiting (shuts down the regulator to prevent overheating) and current limiting (prevents damage from excessive load currents).
Feedback Flexibility: For fixed 5V operation, internal resistors tie the feedback node to GND. Adjustable versions use the ADJ pin to interface with external resistors, enabling custom output voltages.
This architecture balances high current capability, thermal resilience, and precision—suited for industrial applications (e.g., power supplies, embedded systems) requiring reliable 5V power delivery. The inclusion of protection features ensures robustness across diverse operating conditions.

LM1084IS-5.0 Physical Dimension

The LM1084IS - 5.0 uses the TO - 263 (KTT) package. Typical physical dimensions: Length is around 10.16mm. Width (including pin - related structures) is approximately 4.7 - 4.8mm. The maximum seated height (installation height) is about 4.8mm. There are slight differences in details from different data sources (e.g., some mark the length as 10.16mm and width as 8.64mm, possibly due to different measurement references). The core dimensions match the TO - 263 package standard, facilitating circuit layout and mechanical adaptation design. For precise parameters, refer to the official datasheet.

LM1084IS-5.0 Specifications

Parameter	Details
Manufacturer Part Number	LM1084IS-5.0
Category	Integrated Circuits (ICs)
Description	IC REG LIN FIXED POS LDO REG 5V
Manufacturer	Texas Instrument/National Semiconductor
Package / Case	1043
Supplier Device Package	D2PAK/TO-263-3
Package	Bulk
Voltage - Output (Min/Fixed)	5V
Voltage Dropout (Max)	1.5V @ 5A
Voltage - Input (Max)	25V
Output Type	Fixed
Output Configuration	Positive
Number of Regulators	1
Operating Temperature	-40°C to +125°C
Current - Output	5A
Current - Quiescent (Iq)	10 mA
Mounting Type	Surface Mount
Protection Features	Over Current, Over Temperature
PSRR	68 dB (120 Hz)
Package / Case Description	TO-263-4, D²PAK (3 Leads + Tab), TO-263AA

Texas Instruments LM1084IS-5.0 Features

Large output current: The output current can reach 5A, which can meet the power supply requirements of various devices needing larger currents.
Low dropout characteristic: At a 5A load current, the maximum dropout voltage is 1.5V, which helps improve energy efficiency, especially when the input voltage is close to the output voltage.
Excellent regulation performance:
1. The typical line regulation is 0.5mV, which can effectively keep the output voltage stable when the input voltage changes.
2. The typical load regulation is 5mV, so the fluctuation of the output voltage is small when the load current changes within a certain range.
Comprehensive protection functions: It has current limiting and thermal protection functions. When the output current is too large or the device temperature is too high, it can automatically protect to avoid device damage.
Wide temperature range: The operating temperature range is -40°C to 125°C, suitable for various harsh environments such as industrial settings.
Specific package size: It adopts the KTT (TO-263, 3) package with dimensions of 10.16mm × 15.24mm, facilitating installation and layout on the circuit board.
Electrostatic discharge protection: The electrostatic discharge voltage under the human body model (HBM) is ±2000V, which improves the anti-static capability of the device during handling and use.

Texas Instruments LM1084IS-5.0 Advantages

High reliability: A variety of protection circuits, such as current limiting and thermal shutdown, are integrated internally, which greatly reduces the risk of device damage caused by overload, overheating, and other situations, and improves the reliability of the entire circuit system.
Convenient to use: As a fixed output voltage version, it integrates adjustment resistors, eliminating the need for users to design their own resistor networks to set the output voltage. This simplifies the circuit design process, reduces the number of external components, and lowers the complexity and cost of circuit design.
Good stability: It has excellent line regulation and load regulation performance, which can maintain the stability of the output voltage when the input voltage and load current change, providing a stable and reliable power supply for subsequent circuits and ensuring the normal operation of the equipment.
Wide application range: The wide operating temperature range allows it to be used in various extreme temperature environments, not only suitable for general industrial equipment but also able to meet the power supply needs in some special environments.
Compatibility with standard packages: It has the same pin arrangement as Texas Instruments' industrial standard LM317, facilitating users to replace and apply it in familiar circuit designs, and reducing design and migration costs.

Texas Instruments LM1084IS-5.0 Applications

Post-regulator for switching DC/DC converters: The output of switching DC/DC converters may have certain ripple and noise. The LM1084IS-5.0 can be used as a post-regulator to further stabilize the output voltage, reduce ripple, and provide a purer power supply for sensitive circuits.
High-efficiency linear regulator: Due to its low dropout characteristic, it can still maintain high efficiency when the difference between the input voltage and the output voltage is small, making it suitable for occasions with energy efficiency requirements.
Battery chargers: It can provide a stable 5V voltage for battery charging, and ensure the safety and stability of the battery charging process by controlling the charging current, thereby extending the battery life.
Power supply for industrial equipment: In industrial automation, instrumentation, and other equipment, a stable 5V power supply is required. The LM1084IS-5.0, with its wide temperature range and high reliability, is capable of this task.
Consumer electronic devices: Some consumer electronic devices, such as set-top boxes and routers, require a 5V power supply for their internal circuits, and the LM1084IS-5.0 can provide stable power support for them.

LM1084IS-5.0 Alternatives

Model	Output Voltage	Max Output Current	Package Type	Notes
LT1084MK-5	5.0 V	5 A	TO-263	Direct replacement with the same voltage and current
LM1085-5.0	5.0 V	3 A	TO-220 / TO-263	Same family, lower current, pin-compatible
LM1086-5.0	5.0 V	1.5 A	TO-220 / TO-263	Same family, lower current, pin-compatible
LM1084IS-ADJ	Adjustable	5 A	TO-263	Adjustable version, needs external resistors
LM350	Adjustable	3 A	TO-220	General-purpose adjustable regulator
LM317	Adjustable	1.5 A	TO-220	Common adjustable regulator, lower current
LM2940-5.0	5.0 V	~1 A	TO-220 / TO-263	Low dropout fixed regulator, limited current

Comparison: LM1084IS-5.0 vs. LT1084MK-5

Feature	LM1084IS-5.0	LT1084MK-5
Manufacturer	Texas Instruments / National Semiconductor	Analog Devices (formerly Linear Technology)
Output Voltage	Fixed 5.0 V	Fixed 5.0 V
Output Current (Max)	5 A	5 A
Dropout Voltage (Max at 5A)	1.5 V	1.1 V to 1.5 V (typical 1.1V)
Line Regulation (Typ)	0.015%	0.015%
Load Regulation (Typ)	0.1%	0.1%
Thermal Protection	Yes	Yes
Current Limiting	Yes	Yes
Package Type	TO-263 (SMD)	TO-263 (SMD)
Operating Temperature Range	−40°C to +125°C	−55°C to +150°C
Adjustable Version Available	Yes (LM1084IS-ADJ)	Yes (LT1084MK)
Pin Compatibility	Compatible with LM317	Compatible with LM317
Application Focus	General-purpose, industrial	Industrial, military-grade capable
Output Accuracy	±2%	±1% (typical)
Internal Reference	Zener-trimmed bandgap	Precision bandgap
RoHS Compliance	Yes	Yes

LM1084IS-5.0 Manufacturer

The manufacturer of the LM1084IS-5.0 is Texas Instruments (TI for short). Texas Instruments is a world-leading semiconductor design and manufacturing company with a long history and rich experience, enjoying high popularity and influence in the semiconductor industry. Its products are widely used in various fields such as industry, automotive, consumer electronics, and communications, and are renowned for their high quality, high performance, and high reliability. Texas Instruments not only provides various semiconductor devices but also offers customers comprehensive technical support and design resources to help them better apply its products in circuit design and system development.

LM1084IS-5.0 Categroy- Low Dropout Regulator

Low Dropout Regulator (LDO) is a crucial component in power management, designed to maintain stable output voltage even when the input voltage is close to the output. Unlike traditional linear regulators, LDOs operate with minimal voltage difference (dropout) between input and output, enhancing efficiency in low-voltage systems. They integrate reference circuits, error amplifiers, and protection features like current limiting and thermal shutdown, ensuring reliability across varying loads and temperatures.
LDOs are widely used in consumer electronics, industrial equipment, and embedded systems, where stable low-voltage power is critical. A standout example is the Texas Instruments LM1084IS-5.0, a fixed 5V LDO delivering up to 5A. Its low dropout (1.5V at 5A), robust protection, and compact TO-263 package make it ideal for high-current, space-constrained applications, embodying LDOs' core strengths of efficiency and reliability.

LM1084IS-5.0 Datasheets

LM1084IS-5.0 Datasheets.PDF

Conclusion

With its stable 5V output, 5A high - current handling capability, low dropout characteristics, and comprehensive protection features, the LM1084IS - 5.0 has become a reliable choice for power supply design in fields such as industrial control, power electronics, and communication equipment. Whether serving as a main power supply regulator or providing a clean power supply for loads with stringent power supply quality requirements like FPGAs and DSPs, the LM1084IS - 5.0 can demonstrate excellent performance.
Texas Instruments' manufacturing process ensures the consistency and long - term reliability of the device, while the TO - 263 package facilitates thermal design. For applications requiring greater flexibility, the adjustable version (LM1084IS - ADJ) further expands its scope of application. If you are looking for a high - current LDO with both high performance and ease of use, the LM1084IS - 5.0 is worth including in your selection list. Our technical team is always ready to provide you with more detailed technical support and application recommendations.

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