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Microchip Technology LM2575-12BU TR
- Part No.:
- LM2575-12BU TR
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575-12BU TR.pdf
- Description:
- IC REG BUCK 12V 1A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,373
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Product details
Overview
LM2575-12BU TR from Micrel is a fixed-output 12V, 1A step-down (buck) switching regulator in TO-263 package, featuring 52kHz fixed-frequency operation, ±3% output voltage tolerance at 12V, 4V–40V input range, and integrated thermal shutdown and cycle-by-cycle current limiting. It replaces linear regulators in industrial power supplies requiring compact, high-efficiency DC-DC conversion.
For engineers reviewing the LM2575-12BU TR datasheet, LM2575-12BU TR pinout, LM2575-12BU TR application, or LM2575-12BU TR equivalent, key selection criteria include guaranteed 1A output current, TO-263 thermal performance (θJA = 45°C/W with 1 in² copper), 200µA standby current in shutdown mode, and compatibility with standard off-the-shelf 330µH inductors.
Technical Context
The LM2575-12BU TR integrates a 52kHz oscillator, error amplifier with 1.23V internal reference, PWM comparator, and 1A NPN switch driver. Its feedback loop is internally compensated, eliminating external compensation components.
It operates in continuous conduction mode with fixed duty-cycle control; output regulation is achieved by comparing the internal 1.23V reference to the resistor-divided output voltage - though for the fixed 12V version, the feedback network is internal and not user-accessible.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12V ±3% over 0.2–1A load and 15–40V input - ensures stable rail for logic or analog circuitry without external resistors. |
| Max Output Current | 1A continuous - supports mid-power applications like microcontroller boards or sensor modules without external current boosting. |
| Input Voltage Range | 4V to 40V - accommodates wide-input industrial or automotive-derived supplies, including unregulated 24V bus systems. |
| Switching Frequency | 52kHz ±10% - enables use of low-cost, standard 330µH inductors and reduces EMI filtering complexity vs. MHz-range converters. |
| Efficiency | 88% typical at 25VIN/12VOUT/1A - minimizes thermal dissipation, allowing TO-263 operation without heatsink under moderate ambient conditions. |
| Standby Current | <200µA when ON/OFF pin pulled high - enables low-power sleep modes in battery-backed or energy-conscious systems. |
| Protections | Thermal shutdown and cycle-by-cycle current limiting - prevents device failure during overload, short-circuit, or high-temperature operation. |
Pinout & Package
LM2575-12BU TR uses the 5-pin TO-263 (D2Pak) surface-mount package with exposed thermal pad. Pin 1 is VIN, Pin 2 is OUTPUT, Pin 3 is GND, Pin 4 is FEEDBACK (internally connected for fixed 12V version), and Pin 5 is ON/OFF. The tab is electrically connected to Pin 3 (GND).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Unregulated input supply connection | Accepts 4–40V DC; requires local 100µF input capacitor to suppress switching transients. |
| 2 (OUTPUT) | Regulated output node | Drives 1A load; connects to catch diode anode and output filter inductor - must be routed with low-inductance path. |
| 3 (GND) | Power and signal reference ground | Common return for input cap, output cap, and feedback network; tied to exposed thermal pad for heat transfer. |
| 4 (FEEDBACK) | Voltage sense input | Internally connected to 12V divider - no external resistor required; floating or misconnected FB causes regulation failure. |
| 5 (ON/OFF) | Logic-controlled enable/disable | Low-active: ≤0.8V turns on; ≥2.4V disables regulator and reduces quiescent current to <200µA. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12V output | Eliminates external feedback resistors - reduces BOM count, layout area, and calibration risk in production. |
| 52kHz fixed-frequency oscillator | Enables predictable EMI spectrum and simplifies filter design using widely available, low-cost 330µH inductors. |
| Integrated thermal shutdown | Automatically disables switching if junction temperature exceeds ~150°C - protects against sustained overload or poor PCB thermal design. |
| ON/OFF logic control | Supports system-level power sequencing and standby modes with sub-200µA quiescent draw - critical for low-energy IoT nodes. |
| Internal current limit | Peak current limit of 1.3–3.2A prevents MOSFET or inductor saturation during startup or fault - avoids destructive current runaway. |
Applications
| Industrial Power Supply | Microcontroller Board Regulator |
|---|---|
|
Use Scenario: Converting 24V factory bus to stable 12V for PLC I/O modules or motor drivers. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated 12V rail with line/load regulation better than ±3%. Use Value: Replaces linear regulators that would dissipate >12W at 1A - eliminates heatsink and improves system efficiency to 88%. |
Use Scenario: On-board DC-DC conversion for embedded controllers requiring clean 12V for analog peripherals or CAN transceivers. IC Role / Device Role / Timing Role: Compact, self-contained step-down regulator with integrated switch and protection. Use Value: Requires only four external components (input cap, output cap, inductor, catch diode) - accelerates layout and reduces validation effort. |
| Efficient Pre-regulator | On-Card Switching Supply |
|
Use Scenario: Generating intermediate 12V from higher-voltage source before LDO post-regulation to sensitive analog circuits. IC Role / Device Role / Timing Role: High-efficiency pre-converter reducing thermal load on downstream LDOs. Use Value: Delivers 1A at 88% efficiency - cuts pre-regulator losses by >70% versus linear solution, extending board lifetime. |
Use Scenario: Local 12V generation on dense PCBs where space prohibits through-hole TO-220 solutions. IC Role / Device Role / Timing Role: Surface-mount buck regulator with TO-263 thermal pad enabling direct copper pour attachment. Use Value: Achieves θJA = 45°C/W with 1 in² copper - supports 1A continuous operation without heatsink in 70°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575-12WU TR | Same electrical specs and TO-263 package, but RoHS-compliant with high-melting-point solder exemption per Micrel documentation. | Required for new designs targeting EU RoHS compliance; identical thermal and electrical behavior in non-lead-free assembly. | Select LM2575-12WU TR when lead-free manufacturing is mandated; otherwise LM2575-12BU TR remains fully compatible. |
| LM2596-12 | Higher 150kHz switching frequency, 3A rating, and improved 4% output tolerance; requires different inductor value (typically 47–100µH). | Better suited for space-constrained or higher-current designs; not drop-in due to differing frequency, layout, and component values. | Choose LM2596-12 only when upgrading current capability or footprint density - not a pin-compatible replacement for LM2575-12BU TR. |
Compared with LM2575-12WU TR, the LM2575-12BU TR lacks RoHS exemption documentation but shares identical thermal, electrical, and mechanical behavior; versus LM2596-12, it offers proven 52kHz stability and simpler magnetics at the cost of lower current and larger inductor size.
Availability
LM2575-12BU TR is available at Aetrix Electronics and suitable for industrial power supplies, microcontroller board designs, and on-card switching regulators requiring stable component supply across extended product lifecycles.
Supply support for LM2575-12BU TR 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 analog, power management, and timing ICs, acquired by Microchip Technology in 2015. Its products emphasize robustness, ease of use, and industrial-grade reliability.
The LM2575 series was designed as a simple, high-efficiency replacement for three-terminal linear regulators - targeting cost-sensitive, thermally constrained applications in industrial controls, instrumentation, and embedded systems.
FAQ
What is the maximum input voltage for LM2575-12BU TR?
The absolute maximum input voltage for LM2575-12BU TR is 45V, but the recommended operating range is 4V to 40V. Exceeding 40V risks violating the specified operating conditions and may degrade long-term reliability or trigger overvoltage stress on internal components. Always maintain input ripple within datasheet limits and use appropriate input capacitance.
Does LM2575-12BU TR require an external feedback resistor network?
No, LM2575-12BU TR does not require external feedback resistors. As a fixed-output variant, its 12V regulation is implemented internally - Pin 4 (FB) is pre-connected to the internal voltage divider. Connecting external resistors to FB will disrupt regulation and is not supported.
Can LM2575-12BU TR operate without a heatsink?
Yes, LM2575-12BU TR can operate without an external heatsink when mounted on a PCB with ≥1 in² of 2-oz copper connected to the exposed thermal pad, especially at ≤1A load and ambient temperatures ≤70°C. Thermal resistance is specified at θJA = 45°C/W under those conditions.
What is the purpose of the ON/OFF pin on LM2575-12BU TR?
The ON/OFF pin (Pin 5) provides logic-level enable/disable control for LM2575-12BU TR. Driving it to ≥2.4V disables the regulator and reduces quiescent current to <200µA; pulling it ≤0.8V enables normal operation. This allows system-level power sequencing and low-power standby modes.
Which inductor value is recommended for LM2575-12BU TR in standard applications?
A 330µH inductor is the standard recommendation for LM2575-12BU TR, as validated in Micrel's typical application circuits. It balances ripple current, size, and efficiency across the 4–40V input range and 1A load. Inductor saturation current must exceed 2.2A peak to accommodate the internal current limit.
LM2575-12BU TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- 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:
- 1A
- 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
LM2575-12BU TR FAQ
1.How can I place an order for LM2575-12BU TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575-12BU TR 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 LM2575-12BU TR reliable?
The price and inventory of LM2575-12BU TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575-12BU TR is usually 5 days.
3.What payment methods are accepted for LM2575-12BU TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575-12BU TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575-12BU TR?
LM2575-12BU TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575-12BU TR 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 LM2575-12BU TR?
For technical support, including LM2575-12BU TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575-12BU TR requirements.
6.How does Aetrix verify that LM2575-12BU TR is sourced from the original manufacturer or authorized distributors?
All LM2575-12BU TR 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 LM2575-12BU TR meets industry standards.
7.What is the process for return or replacement of LM2575-12BU TR?
All LM2575-12BU TR units undergo pre-shipment inspection (PSI). If there is an issue with LM2575-12BU TR, 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 LM2575-12BU TR part is unused and in its original packaging.
Return procedure for LM2575-12BU TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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