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Microchip Technology LM2576WT
- Part No.:
- LM2576WT
- Manufacturer:
- Microchip Technology
- Package:
- TO-220-5
- Datasheet:
-
LM2576WT.pdf
- Description:
- IC REG BUCK ADJ 3A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:193
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Product details
Overview
LM2576WT from Micrel is a fixed-frequency, monolithic step-down (buck) switching regulator IC in TO-220-5 package, delivering up to 3A output current with ±3% output voltage accuracy at 5V, 52kHz internal oscillator frequency, and 4V–40V input voltage range. It integrates thermal shutdown, cycle-by-cycle current limiting, and ON/OFF control for reliable DC-DC conversion in industrial power supplies.
For engineers reviewing the LM2576WT datasheet, LM2576WT pinout, LM2576WT application, or LM2576WT equivalent, this device is selected for high-efficiency buck regulation where minimal external components (only 4 required), low standby current (<200µA), and robust fault protection are critical design requirements.
Technical Context
The LM2576WT implements a fixed-frequency PWM architecture with internal 52kHz oscillator, error amplifier, bandgap reference (1.23V), and 3A NPN switch. Feedback is taken from the output via resistive divider to the FB pin, enabling precise regulation without external compensation.
It features integrated thermal shutdown triggered at ~150°C junction temperature and cycle-by-cycle current limiting with 5.8A typical peak limit. The ON/OFF pin accepts TTL/CMOS-compatible logic levels (VIH ≥ 2.2V, VIL ≤ 1.0V) to enable/disable regulation with <200µA standby current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | Guaranteed 3A continuous load capability - supports mid-power embedded systems without external current boosting. |
| Input Voltage Range | 4V to 40V - accommodates wide-input industrial, automotive, and telecom supply rails including unregulated 24V or 36V sources. |
| Output Voltage | Fixed 5.0V ±3% over full temperature and load range - eliminates need for external feedback resistors in standard 5V rail generation. |
| Oscillator Frequency | 52kHz ±10% - enables use of low-cost, standard-value inductors (e.g., 330µH) and reduces EMI compared to higher-frequency alternatives. |
| Efficiency | 82% typical at VIN=12V, VOUT=5V, IOUT=3A - significantly reduces heat dissipation versus linear regulators, often eliminating heatsink requirement. |
| Standby Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-backed or energy-conscious systems. |
| Thermal Protection | Internal thermal shutdown at TJ ≈ 150°C - prevents catastrophic failure during overload or poor heatsinking conditions. |
Pinout & Package
LM2576WT is housed in a 5-lead TO-220 package with exposed tab (pin 3) for thermal conduction and mechanical mounting. The package provides θJA = 65°C/W (no heatsink) or 45°C/W (with 4 in² PCB copper), supporting direct bolt-on heatsink attachment.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Unregulated input supply connection | Accepts 4V–40V DC; must be decoupled with ≥100µF electrolytic capacitor near pin to suppress input ripple and transient spikes. |
| 2 - OUTPUT | Switched output node | Drives external catch diode and inductor; carries high di/dt switching current - requires short, low-inductance PCB trace routing. |
| 3 - GND | Power ground / case tab | Primary return path for input/output currents and thermal interface; must be connected to large copper area or heatsink for thermal management. |
| 4 - FEEDBACK | Regulation sense input | Internally referenced to 1.23V; for fixed 5V version, this pin is internally tied - no external resistor network required. |
| 5 - ON/OFF | Enable/disable control input | Active-low logic: ≤1.0V disables regulator (output off, IQ <200µA); ≥2.2V enables operation; open-circuit defaults to enabled. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 3A NPN switch | Eliminates need for external MOSFET or transistor - reduces BOM count and layout complexity in compact designs. |
| Fixed 5V output with ±3% tolerance | Guaranteed accuracy across –40°C to +85°C and 0.5A–3A load - simplifies compliance testing and eliminates calibration steps. |
| 52kHz fixed-frequency operation | Enables predictable EMI filtering and compatibility with low-cost, high-saturation-current inductors (e.g., AIE 415-0926). |
| Cycle-by-cycle current limiting | Protects against short-circuit and overload by limiting peak switch current to ≥4.2A - maintains regulation during transient faults. |
| Thermal shutdown with hysteresis | Shuts down at ~150°C junction temperature and restarts after cooldown - prevents thermal runaway without external circuitry. |
Applications
| Industrial Power Supply | Embedded System Pre-regulator |
|---|---|
|
Use Scenario: Converting 24V rail to stable 5V for PLC I/O modules operating in ambient temperatures up to 70°C. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated, regulated 5V supply with built-in fault protection. Use Value: Delivers 3A continuously with 82% efficiency, reducing board-level heat generation and eliminating need for forced-air cooling. |
Use Scenario: Generating clean 5V intermediate rail from noisy 12V automotive battery supply for microcontroller and sensor subsystems. IC Role / Device Role / Timing Role: High-efficiency pre-regulator stepping down input before low-noise LDO stages. Use Value: Maintains ±3% output accuracy despite 4V–40V input variation and load transients up to 3A, improving downstream system stability. |
| On-Board DC-DC Converter | Positive-to-Negative Inverter |
|
Use Scenario: On-card 5V generation in networking equipment where space and component count are constrained. IC Role / Device Role / Timing Role: Standalone buck converter requiring only four external components (inductor, diode, two capacitors). Use Value: Reduces total solution size and cost versus discrete switcher designs while meeting EN55022 Class B conducted EMI limits. |
Use Scenario: Generating –5V rail from +12V supply for op-amp biasing in analog signal conditioning circuits. IC Role / Device Role / Timing Role: Configured as inverting buck-boost converter using standard external components. Use Value: Achieves regulated negative output without dedicated inverting IC - leverages same 52kHz timing and protection features as buck mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576T-5.0 | Same electrical specs and TO-220-5 package; differs only in manufacturer marking and RoHS status (LM2576WT is RoHS-compliant with hot-melt exemption). | No functional difference; identical pinout, thermal performance, and reliability profile. | Select LM2576WT when RoHS compliance with exemption is required per procurement policy. |
| LM2596T-5.0 | Higher 150kHz switching frequency, lower 3A max output current, improved 4% output accuracy, and different pinout (TO-220-5 but pin 3 = VIN, not GND). | Requires PCB redesign due to non-pin-compatible layout and different external component values (e.g., 68µH inductor vs. 330µH). | Choose LM2596T-5.0 only if higher frequency and smaller magnetics are prioritized over drop-in replacement capability. |
Compared with LM2576T-5.0, LM2576WT offers identical functionality with certified RoHS compliance; versus LM2596T-5.0, it provides proven 52kHz stability and direct compatibility with legacy 330µH inductor designs, avoiding layout rework.
Availability
LM2576WT is available at Aetrix Electronics and suitable for industrial power supplies, embedded system pre-regulators, and on-board DC-DC converters requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for LM2576WT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Micrel, Inc. was a U.S.-based semiconductor company specializing in power management, analog, and RF solutions before its acquisition by Microchip Technology in 2015. Its products emphasized integration, reliability, and ease-of-use for industrial and communications markets.
The LM2576WT belongs to Micrel's LM2576 series of monolithic buck regulators, designed specifically to replace linear regulators in medium-power applications where efficiency, thermal performance, and minimal external components are essential.
FAQ
What is the maximum input voltage rating for the LM2576WT?
The LM2576WT has an absolute maximum input voltage rating of 45V, with recommended operating range of 4V to 40V. Exceeding 40V during normal operation risks violating the guaranteed electrical specifications, though brief transients up to 45V are tolerated without damage per Absolute Maximum Ratings.
Does the LM2576WT require external feedback resistors to set the output voltage?
No, the LM2576WT is the fixed 5V output variant - its feedback network is fully internal. Pin 4 (FEEDBACK) is internally connected to the 1.23V reference and output divider, so no external resistors are needed. This distinguishes it from the adjustable LM2576T-ADJ version.
Can the LM2576WT be used in a negative-output (inverting) configuration?
Yes, the LM2576WT can be configured as a positive-to-negative inverting buck-boost converter using standard external components (inductor, diode, capacitors). The datasheet explicitly lists "Positive to negative converter (inverting Buck-Boost)" as a typical application, leveraging the same internal switch and control architecture.
What thermal management is required for full 3A operation of the LM2576WT?
At 3A output with 12V input and 5V output, the LM2576WT dissipates ~2.1W. With θJA = 65°C/W (no heatsink), junction temperature rise would exceed safe limits. A minimum 4 in² copper pour or small clip-on heatsink is required to maintain TJ < 125°C under continuous load.
Is the LM2576WT pin-compatible with other members of the LM2576 family?
Yes, all LM2576 variants in TO-220-5 package - including LM2576T-3.3, LM2576T-12, LM2576T-ADJ, and LM2576WT - share identical pinout (VIN, OUTPUT, GND, FEEDBACK, ON/OFF) and mechanical footprint, enabling direct substitution where output voltage and RoHS requirements align.
LM2576WT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-220-5
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 37V
- Current - Output:
- 3A
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-5
LM2576WT FAQ
1.How can I place an order for LM2576WT through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576WT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM2576WT reliable?
The price and inventory of LM2576WT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576WT is usually 5 days.
3.What payment methods are accepted for LM2576WT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576WT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576WT?
LM2576WT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576WT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM2576WT?
For technical support, including LM2576WT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576WT requirements.
6.How does Aetrix verify that LM2576WT is sourced from the original manufacturer or authorized distributors?
All LM2576WT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM2576WT meets industry standards.
7.What is the process for return or replacement of LM2576WT?
All LM2576WT units undergo pre-shipment inspection (PSI). If there is an issue with LM2576WT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM2576WT part is unused and in its original packaging.
Return procedure for LM2576WT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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