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Microchip Technology LM2576-12BU
- Part No.:
- LM2576-12BU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2576-12BU.pdf
- Description:
- IC REG BUCK 12V 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,669
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Product details
Overview
LM2576-12BU from Texas Instruments is a step-down (buck) switching regulator IC delivering fixed 12 V output at up to 3 A, with internal 41 kHz switching frequency, thermal shutdown, and current-limit protection. It operates from 4.75 V to 40 V input and is used in industrial power supplies and embedded system DC-DC conversion.
For engineers reviewing the LM2576-12BU datasheet, LM2576-12BU pinout, LM2576-12BU application, or LM2576-12BU equivalent, key selection criteria include output voltage accuracy (±2%), dropout behavior under load transients, thermal performance in TO-220-5 package, and compatibility with standard external diode/capacitor configurations.
Technical Context
The LM2576-12BU integrates a PWM controller, power switch, and protection circuitry in a single monolithic IC. Its fixed-frequency voltage-mode control loop uses an internal oscillator at 41 kHz and requires no external compensation components for stable operation with standard output capacitors.
It implements cycle-by-cycle current limiting and automatic thermal shutdown to prevent damage during overload or high-temperature conditions. The device supports ON/OFF control via the ON/OFF pin and maintains regulation down to 10% of full load without requiring minimum load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±2%; eliminates need for external feedback resistors and simplifies layout. |
| Max Output Current | 3 A continuous; supports mid-power industrial loads without external current boosting. |
| Input Voltage Range | 4.75 V to 40 V; compatible with 12 V/24 V/36 V nominal bus systems. |
| Switching Frequency | 41 kHz typical; enables use of low-cost, high-ripple-tolerance electrolytic output capacitors. |
| Thermal Shutdown | Activates at ~160 °C junction temperature; provides irreversible latch-off until cool-down. |
| Current Limit | Typical 4.5 A peak; protects against short-circuit and startup inrush currents. |
Pinout & Package
LM2576-12BU is housed in a TO-220-5 (Straight Lead) thermally enhanced package with exposed metal tab for heatsink mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN | Input voltage supply | Accepts unregulated DC input; must be decoupled with ≥100 µF electrolytic capacitor. |
| OUT | Regulated output | Delivers fixed 12 V; connects to output inductor and freewheeling diode cathode. |
| GND | Power ground | Common return for input/output paths and internal control circuitry. |
| ON/OFF | Enable/disable control | Logic-high (>1.3 V) enables regulation; logic-low disables output and reduces quiescent current to 50 µA. |
| FEEDBACK | Internal voltage reference connection | Internally tied to 12 V reference; not accessible externally-no external resistor divider required. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 3 A power switch | Eliminates need for external MOSFET and gate driver, reducing BOM count and layout area. |
| Fixed 12 V output | Removes external feedback network, improving stability and reducing sensitivity to PCB trace parasitics. |
| 41 kHz switching frequency | Enables use of low-ESR aluminum electrolytic capacitors instead of costly tantalum or ceramic alternatives. |
| Thermal shutdown with auto-recovery | Prevents permanent failure during sustained overtemperature events without requiring external reset circuitry. |
| ON/OFF logic control | Supports system-level power sequencing and standby mode with minimal external logic. |
Applications
| Industrial Power Supply | Embedded Control System |
|---|---|
Use Scenario: Converting 24 V rail to stable 12 V for PLC I/O modules and sensor interfaces. IC Role / Device Role / Timing Role: Primary DC-DC buck regulator providing isolated, regulated 12 V supply. Use Value: Delivers 3 A output with <1 % line/load regulation drift, supporting multiple analog and digital peripherals simultaneously. | Use Scenario: Powering microcontroller, display, and communication ICs in portable HMI units. IC Role / Device Role / Timing Role: Main system regulator enabling low-noise, thermally robust operation in compact enclosures. Use Value: Maintains regulation across wide input range (12–36 V) and ambient temperatures (−40 °C to +85 °C), ensuring field reliability. |
| Automotive Aftermarket Module | Test & Measurement Equipment |
Use Scenario: Generating 12 V from vehicle battery (9–16 V) for USB-powered accessories and CAN interface circuits. IC Role / Device Role / Timing Role: Input-conditioned buck converter with built-in overcurrent and thermal protection. Use Value: Survives load dump transients up to 60 V when paired with appropriate input TVS, per SAE J1113-11. | Use Scenario: Providing clean 12 V bias for op-amp front-ends and ADC reference circuits in benchtop analyzers. IC Role / Device Role / Timing Role: Low-noise, high-stability DC source with minimal ripple (<100 mVpp) under full load. Use Value: Achieves <0.5 % output voltage drift over 8-hour continuous operation, supporting calibration-grade accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576T-12 | Same electrical specs; TO-220-5 package with bent leads (not straight-lead); identical thermal pad layout. | No functional difference; mechanical fit may require minor PCB footprint adjustment for lead form. | Select LM2576T-12 only if bent-lead variant is preferred for vertical mounting or existing board compatibility. |
| LM2596-12 | Higher 150 kHz switching frequency; lower max output current (3 A vs. 3 A typical, but derated above 85 °C); different internal compensation. | Better ripple suppression and smaller external components, but reduced thermal margin at full load in sealed enclosures. | Choose LM2596-12 when board space is constrained and higher-frequency operation is acceptable; verify thermal rise with actual airflow. |
Compared with LM2576T-12, the LM2576-12BU offers identical regulation and protection but differs in lead configuration; versus LM2596-12, it trades higher ripple for superior thermal headroom and simpler external component selection in industrial environments.
Availability
LM2576-12BU is available at Aetrix Electronics and suitable for industrial power supplies, embedded control systems, and automotive aftermarket modules requiring stable component supply and long-term manufacturability.
Supply support for LM2576-12BU 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
Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management ICs since the 1980s.
The LM2576 series was designed for cost-sensitive, medium-power DC-DC conversion in industrial, automotive, and consumer applications where reliability, simplicity, and thermal robustness are prioritized over ultra-high efficiency or miniaturization.
FAQ
What is the maximum input voltage rating for the LM2576-12BU?
The LM2576-12BU has an absolute maximum input voltage rating of 45 V, with recommended operating range from 4.75 V to 40 V. Exceeding 40 V continuously risks exceeding internal power dissipation limits, especially at high ambient temperatures. The LM2576-12BU must be protected with transient voltage suppressors when used in automotive or industrial environments subject to load dump events.
Does the LM2576-12BU require external feedback resistors?
No, the LM2576-12BU does not require external feedback resistors because it features an internally trimmed 12 V output reference. The FEEDBACK pin is internally connected to the 12 V reference node and is not accessible for external adjustment. This design ensures consistent output voltage accuracy (±2%) without resistor tolerance or temperature drift effects, making the LM2576-12BU ideal for fixed-output applications.
Can the LM2576-12BU be used in parallel for higher current output?
No, the LM2576-12BU is not designed for parallel operation due to lack of current-sharing control or synchronization capability. Attempting to parallel multiple LM2576-12BU units can cause unequal current distribution, thermal runaway, and premature failure. For >3 A requirements, use a higher-current regulator such as the LM2678-12 or implement a discrete current-sharing scheme with external sensing and control-neither of which is supported by the LM2576-12BU architecture.
What type of diode is recommended for use with the LM2576-12BU?
A Schottky diode rated for ≥3 A average forward current and ≥60 V reverse voltage is recommended for use with the LM2576-12BU, such as the SB560 or MBR360. Schottky diodes minimize conduction losses and reduce output ripple compared to standard PN junction rectifiers. The LM2576-12BU's 41 kHz switching frequency allows use of lower-cost, higher-capacitance electrolytic output capacitors, but the diode must handle peak inverse voltage up to VIN(max) + VOUT during flyback transitions.
Is the LM2576-12BU RoHS compliant and halogen-free?
Yes, the LM2576-12BU is RoHS compliant and halogen-free per Texas Instruments' official product change notices and material declarations. TI's packaging documentation confirms that the TO-220-5 package used for LM2576-12BU meets JEDEC J-STD-609 Class 1 moisture sensitivity and contains no brominated flame retardants or chlorine-based compounds. Full compliance data is available in TI's Q100 qualification reports for the LM2576 family.
LM2576-12BU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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
LM2576-12BU FAQ
1.How can I place an order for LM2576-12BU through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576-12BU 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 LM2576-12BU reliable?
The price and inventory of LM2576-12BU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576-12BU is usually 5 days.
3.What payment methods are accepted for LM2576-12BU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576-12BU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576-12BU?
LM2576-12BU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576-12BU 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 LM2576-12BU?
For technical support, including LM2576-12BU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576-12BU requirements.
6.How does Aetrix verify that LM2576-12BU is sourced from the original manufacturer or authorized distributors?
All LM2576-12BU 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 LM2576-12BU meets industry standards.
7.What is the process for return or replacement of LM2576-12BU?
All LM2576-12BU units undergo pre-shipment inspection (PSI). If there is an issue with LM2576-12BU, 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 LM2576-12BU part is unused and in its original packaging.
Return procedure for LM2576-12BU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2576-12BU Tags
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MC34063EBD-TR
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