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Microchip Technology LM2576-12WU
- Part No.:
- LM2576-12WU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2576-12WU.pdf
- Description:
- IC REG BUCK 12V 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:225
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Product details
Overview
LM2576-12WU from Micrel is a fixed-output 12V, 3A step-down (buck) switching regulator in TO-263-5 package, featuring 52kHz fixed-frequency operation, ±3% output voltage tolerance over line/load, thermal shutdown, cycle-by-cycle current limiting, and <200µA standby current. It replaces linear regulators in industrial power supplies requiring high efficiency and minimal heatsinking.
For engineers reviewing the LM2576-12WU datasheet, LM2576-12WU pinout, LM2576-12WU application, or LM2576-12WU equivalent, key selection criteria include input voltage range (4–40V), guaranteed 3A output, fixed 12V output with ±3% accuracy, TO-263 thermal performance, and ON/OFF control interface compatibility.
Technical Context
The LM2576-12WU integrates a 3A NPN switch, 52kHz oscillator, error amplifier, bandgap reference (1.23V), and thermal/current protection circuitry. Its feedback loop is internally compensated and configured for fixed 12V output - no external resistor divider required.
It operates in continuous conduction mode with up to 98% duty cycle, supports input voltages from 4V to 40V, and delivers regulated 12V output across load currents of 0.5A to 3A and junction temperatures from –40°C to +125°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12V ±3% (min 11.52V, max 12.48V at 0.5–3A, 15–40VIN) - ensures stable rail for 12V logic or analog subsystems without trimming. |
| Max Output Current | 3A DC - supports mid-power applications like motor drivers or FPGA I/O banks without external current boosting. |
| Input Voltage Range | 4V to 40V - accommodates wide-input industrial, automotive, or battery-backed systems (e.g., 12V/24V nominal buses). |
| Switching Frequency | 52kHz ±10% - enables use of low-cost, standard 330µH inductors and simplifies EMI filtering vs. MHz-range converters. |
| Efficiency | 88% at VIN = 25V, IOUT = 3A, VOUT = 12V - reduces thermal load vs. linear regulators; often eliminates heatsink in PCB-mounted designs. |
| Standby Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-powered or energy-conscious systems. |
| Thermal Protection | Internal thermal shutdown with 100% burn-in - prevents catastrophic failure during overload or poor airflow conditions. |
Pinout & Package
LM2576-12WU uses the 5-lead TO-263 (surface-mount) package with exposed thermal pad. Pin 1 is VIN, Pin 2 is OUTPUT, Pin 3 is GND, Pin 4 is FEEDBACK (internally tied for fixed 12V), and Pin 5 is ON/OFF. The package provides lower thermal resistance than TO-220 and is compatible with reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Unregulated input supply connection | Accepts 4–40V DC; requires ≥100µF input capacitance near pin for stability and ripple suppression. |
| 2 - OUTPUT | Regulated 12V output node | Drives 3A load; connects to catch diode anode and output capacitor; high-current path requiring wide PCB traces. |
| 3 - GND | Power and signal ground reference | Common return for input/output capacitors, inductor, and feedback network; must be low-impedance single-point or ground plane. |
| 4 - FEEDBACK | Internal voltage sense input | Internally connected to 12V divider; not user-accessible - no external resistors needed for fixed-output operation. |
| 5 - ON/OFF | Logic-controlled enable/disable input | Active-low disable: ≤0.8V (max) turns off regulator; ≥2.2V (min) enables operation; draws ≤30µA when active. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12V output | Eliminates external feedback resistors - reduces BOM count, layout area, and calibration risk in production. |
| Integrated 3A switch | Removes need for external MOSFET and driver - simplifies design and improves reliability over discrete buck controllers. |
| 52kHz oscillator | Enables use of off-the-shelf, low-DCR, non-shielded inductors (e.g., 330µH) - lowers cost and size vs. high-frequency alternatives. |
| ON/OFF control | Supports system-level power sequencing and standby modes with <200µA quiescent draw - critical for energy certification. |
| Thermal + current protection | Self-protecting under short-circuit, overtemperature, or overload - avoids external fault-handling circuitry and field failures. |
Applications
| Industrial Power Supply | Automotive Body Control Module |
|---|---|
|
Use Scenario: Converting 24V vehicle battery or 24V industrial bus to stable 12V for microcontrollers, sensors, and actuators. IC Role / Device Role / Timing Role: Primary DC-DC buck regulator providing isolated, regulated 12V rail with built-in fault protection. Use Value: Delivers 3A at 88% efficiency with no heatsink required - reduces board space and thermal management complexity in sealed enclosures. |
Use Scenario: Powering CAN transceivers, LIN nodes, and door/window control ICs in 12V automotive subsystems. IC Role / Device Role / Timing Role: Fixed-output buck converter supplying clean 12V from noisy, wide-range battery input (7–40V). Use Value: Withstands cold-crank (4V) and load-dump (40V) transients per ISO 7637-2; ±3% output ensures reliable logic-level operation. |
| Embedded System Backplane | POS Terminal Power Rail |
|
Use Scenario: Generating local 12V from a shared 24V or 48V backplane in modular industrial PCs or PLC I/O carriers. IC Role / Device Role / Timing Role: On-card point-of-load regulator delivering low-noise 12V to FPGAs, ADCs, and communication interfaces. Use Value: 52kHz switching allows effective LC filtering; TO-263 thermal pad enables direct mounting to copper pour for consistent 3A delivery. |
Use Scenario: Providing regulated 12V to receipt printers, barcode scanners, and display backlight drivers in retail POS terminals. IC Role / Device Role / Timing Role: High-reliability buck regulator powering multiple peripherals from AC/DC adapter or UPS backup. Use Value: Internal current limiting and thermal shutdown prevent damage during printer motor stall or scanner laser surge events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576-12T | Same electrical specs, but TO-220-5 through-hole package with higher θJA (65°C/W vs. ~45°C/W for TO-263) | Requires heatsink above ~1.5A in still air; less suitable for dense SMT layouts | Select LM2576-12T only if through-hole assembly or legacy footprint compatibility is mandatory. |
| MP1584EN-LF-Z | 40V input, 3A, adjustable output (1.2–28V); 1.5MHz switching; requires external feedback resistors | Higher frequency enables smaller magnetics but increases EMI sensitivity and layout complexity | Choose MP1584EN-LF-Z when board space is constrained and adjustable output or faster transient response is needed. |
Compared with LM2576-12T, LM2576-12WU offers superior thermal performance in SMT designs; compared with MP1584EN-LF-Z, it trades higher-frequency flexibility for simplicity, robustness, and reduced EMI filter burden in industrial environments.
Availability
LM2576-12WU is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and embedded backplane applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for LM2576-12WU 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. Known for rugged, easy-to-use integrated regulators.
The LM2576 series was designed as a drop-in, high-efficiency replacement for three-terminal linear regulators in industrial and automotive power conversion - prioritizing simplicity, reliability, and thermal resilience over ultra-high density.
FAQ
What is the maximum input voltage rating for LM2576-12WU?
The absolute maximum input voltage for LM2576-12WU is 45V, but the recommended operating range is 4V to 40V. Exceeding 40V risks violating the device's safe operating area, especially under high ambient temperature or full load. The LM2576-12WU datasheet specifies guaranteed performance only within 4–40V, with thermal derating applied above 35V at 3A.
Does LM2576-12WU require external feedback resistors?
No, LM2576-12WU does not require external feedback resistors. As a fixed-output variant, its internal voltage divider is factory-trimmed to deliver 12V ±3%. Pin 4 (FEEDBACK) is internally connected and not accessible - unlike the adjustable LM2576 versions, no resistor network is needed for regulation.
Can LM2576-12WU be used in automotive cold-crank conditions?
Yes, LM2576-12WU supports input voltages down to 4V, making it suitable for automotive cold-crank scenarios where battery voltage dips below 6V. Its guaranteed operation from 4V to 40V, combined with thermal shutdown and current limiting, ensures robust behavior during transient low-voltage events without latch-up or damage.
What is the thermal resistance (θJA) of LM2576-12WU in typical PCB layout?
For LM2576-12WU in TO-263-5 package, θJA is approximately 45°C/W with 1 square inch of 2-oz copper connected to the thermal pad. This value assumes proper soldering of the exposed pad and minimal trace length. Without copper pour, θJA rises significantly - always follow Micrel's layout guidelines to maintain thermal performance at 3A load.
How does the ON/OFF pin function on LM2576-12WU?
The ON/OFF pin (Pin 5) of LM2576-12WU is a logic-level enable input: applying ≥2.2V enables regulation, while ≤0.8V disables it. In shutdown, LM2576-12WU draws <200µA total supply current. The pin tolerates up to 40V and sinks <30µA when enabled - allowing direct interfacing with microcontroller GPIO or open-collector drivers without level shifting.
LM2576-12WU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263-5
LM2576-12WU FAQ
1.How can I place an order for LM2576-12WU through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576-12WU 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 LM2576-12WU reliable?
The price and inventory of LM2576-12WU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576-12WU is usually 5 days.
3.What payment methods are accepted for LM2576-12WU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576-12WU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576-12WU?
LM2576-12WU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576-12WU 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 LM2576-12WU?
For technical support, including LM2576-12WU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576-12WU requirements.
6.How does Aetrix verify that LM2576-12WU is sourced from the original manufacturer or authorized distributors?
All LM2576-12WU 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 LM2576-12WU meets industry standards.
7.What is the process for return or replacement of LM2576-12WU?
All LM2576-12WU units undergo pre-shipment inspection (PSI). If there is an issue with LM2576-12WU, 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 LM2576-12WU part is unused and in its original packaging.
Return procedure for LM2576-12WU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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