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Microchip Technology LM2575-12WT
- Part No.:
- LM2575-12WT
- Manufacturer:
- Microchip Technology
- Package:
- TO-220-5
- Datasheet:
-
LM2575-12WT.pdf
- Description:
- IC REG BUCK 12V 1A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,566
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Product details
Overview
LM2575-12WT from Micrel Inc. is a fixed-output 12V, 1A step-down (buck) switching regulator in a 5-pin TO-220 package. It operates at a fixed 52kHz switching frequency, supports 4V–40V input, delivers ±3% output voltage accuracy across load and line variations, and integrates thermal shutdown, cycle-by-cycle current limiting, and ON/OFF control - ideal for industrial power supplies requiring compact, heat-sink-free 12V conversion.
For engineers reviewing the LM2575-12WT datasheet, LM2575-12WT pinout, LM2575-12WT application, or LM2575-12WT equivalent, key selection criteria include guaranteed 1A output current, 88% typical efficiency at 12V/1A, 200µA standby quiescent current, TO-220 thermal resistance (θJA = 65°C/W), and compatibility with standard off-the-shelf 330µH inductors.
Technical Context
The LM2575-12WT implements a monolithic buck regulator architecture with an internal 52kHz oscillator, fixed-gain error amplifier, 1.23V bandgap reference, and integrated 1A NPN switch. Feedback is internally connected to set 12V output - no external resistor divider required.
It features cycle-by-cycle current limiting (1.7–3.2A peak), thermal shutdown activation at ~150°C junction temperature, and ON/OFF control via pin 5 with logic-compatible thresholds (VIH ≥ 2.2V, VIL ≤ 1.0V). The device requires only four external components: input capacitor, output capacitor, catch diode, and inductor.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12V ±3% over 0.2–1A load and 15–40V input - eliminates need for feedback resistors and ensures stable rail for microcontrollers or analog circuitry. |
| Max Output Current | 1A continuous - sufficient to power multiple ICs or small subsystems without external current boosting. |
| Input Voltage Range | 4V to 40V - supports wide-input industrial, automotive, and telecom applications including unregulated 24V or 36V bus conversion. |
| Switching Frequency | 52kHz ±10% - enables use of low-cost, high-current standard inductors (e.g., 330µH) and reduces EMI filtering complexity vs. MHz-range regulators. |
| Efficiency | 88% typical at VIN = 25V, VOUT = 12V, IOUT = 1A - minimizes power loss and thermal stress, often eliminating heatsink requirements in ambient ≤50°C. |
| Standby Quiescent Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-backed or energy-conscious systems. |
| Thermal Protection | Internal thermal shutdown with automatic recovery - prevents permanent damage during overload or poor heatsinking conditions. |
Pinout & Package
LM2575-12WT is housed in a 5-pin TO-220 package with exposed tab (pin 3) serving as GND and thermal path. Mounting orientation is vertical with 1/2″ leads in socket or PCB; θJA = 65°C/W (no heatsink), improving to 45°C/W with 4 in² copper area.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: VIN | Input supply connection | Accepts 4–40V DC; requires ≥100µF low-ESR input capacitor near pin to suppress switching transients. |
| 2: OUTPUT | Switch node / power output | Drives external catch diode and inductor; high dI/dt node requiring short PCB trace routing. |
| 3: GND | Power ground / thermal tab | Primary return path and thermal interface; must be soldered to large copper pour for thermal performance. |
| 4: FEEDBACK | Internal 12V regulation reference | Internally tied to 12V output - not user-accessible; no external resistor network needed. |
| 5: ON/OFF | Logic-controlled enable/disable | Active-low disable: <1.0V = ON, >2.2V = OFF; draws <30µA when enabled, <200µA when disabled. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12V output | Eliminates external feedback resistors - reduces BOM count, layout area, and calibration drift risk. |
| Integrated 1A NPN switch | Removes need for external MOSFET and gate driver - simplifies design and improves reliability in cost-sensitive applications. |
| 52kHz fixed-frequency operation | Enables predictable EMI spectrum and compatibility with low-cost, high-saturation-current inductors (e.g., AIE 415-0926). |
| Thermal shutdown + current limit | Provides autonomous fault protection without external sensing - essential for unattended industrial equipment. |
| ON/OFF pin with µA-level standby | Supports system-level power sequencing and low-power sleep states while maintaining fast wake-up response. |
Applications
| Industrial Power Supply | Embedded Control Board |
|---|---|
|
Use Scenario: Converting 24VDC factory bus to regulated 12V for PLC I/O modules and sensor interfaces. IC Role / Device Role / Timing Role: Primary step-down regulator providing isolated 12V rail with line/load regulation and thermal resilience. Use Value: Delivers 1A at 88% efficiency with no heatsink required below 50°C ambient - reduces enclosure size and cooling cost. |
Use Scenario: On-board 12V generation for microcontroller peripherals, op-amps, and communication transceivers. IC Role / Device Role / Timing Role: Compact, self-contained buck converter replacing linear regulators to avoid thermal derating. Use Value: Reduces board space and heat dissipation versus 7812 linear regulator - enables higher integration density in fanless enclosures. |
| Telecom Remote Unit | Test Equipment Power Module |
|
Use Scenario: Deriving 12V from 48V PoE-derived or battery-backed input in outdoor base station units. IC Role / Device Role / Timing Role: Input-flexible buck regulator supporting wide VIN range and robust fault handling. Use Value: Withstands 40V max input and includes thermal/current protection - improves field reliability under voltage surges or short circuits. |
Use Scenario: Programmable 12V source in benchtop power supplies or automated test fixtures. IC Role / Device Role / Timing Role: Stable, low-noise DC-DC stage enabling precise voltage margining and remote ON/OFF control. Use Value: ON/OFF pin allows synchronized startup/shutdown with host controller; ±3% output tolerance meets lab-grade accuracy needs. |
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 | Same electrical specs, but in TO-263 (D2PAK) package with lower θJA (45°C/W with 1 in² copper) and surface-mount footprint. | Better thermal performance in space-constrained SMT designs; requires reflow-compatible layout and no through-hole mounting. | Select LM2575-12WU for automated assembly and improved thermal management on dense PCBs; LM2575-12WT remains optimal for through-hole prototyping or heatsink-integrated chassis mounts. |
| LM2576-12 | Higher 3A output capability, 52kHz frequency, but larger dropout (≥3V) and higher quiescent current (~5mA vs. <200µA). | Suitable for higher-current loads but less efficient at light loads and incompatible with ultra-low-power standby requirements. | Choose LM2576-12 only if >1A output is needed; LM2575-12WT is superior for 1A applications where standby current, board area, and thermal simplicity are prioritized. |
Compared with LM2575-12WU, the LM2575-12WT offers easier mechanical mounting and heatsink integration, while LM2576-12 trades off standby efficiency and footprint for higher current headroom - making LM2575-12WT the optimal balance for 1A, thermally constrained, or through-hole production environments.
Availability
LM2575-12WT is available at Aetrix Electronics and suitable for industrial power supplies, embedded control boards, telecom remote units, and test equipment power modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for LM2575-12WT 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 solutions before its acquisition by Microchip Technology in 2015. Its legacy power ICs remain widely deployed in industrial and infrastructure systems.
The LM2575 series was designed as a drop-in, high-efficiency replacement for three-terminal linear regulators - targeting cost-sensitive, thermally constrained applications where simplicity, reliability, and minimal external components were critical.
FAQ
What is the maximum input voltage rating for the LM2575-12WT?
The LM2575-12WT has an absolute maximum input voltage of 45V, with recommended operating range up 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 within 4–40V for guaranteed performance per the datasheet.
Does the LM2575-12WT require external feedback resistors to set the output voltage?
No - the LM2575-12WT is a fixed-output variant with internal feedback network configured for 12V. Pin 4 (FEEDBACK) is internally connected and not accessible to the user. This eliminates resistor tolerance errors, layout sensitivity, and BOM overhead associated with adjustable versions like the LM2575-ADJ.
Can the LM2575-12WT operate without a heatsink?
Yes - the LM2575-12WT can operate without an external heatsink at full 1A load in ambient temperatures ≤50°C when mounted vertically on a PCB with ≥4 in² of copper area around the tab (θJA ≈ 45°C/W). At higher ambient or with minimal copper, thermal derating or heatsink addition is required to stay within 125°C max junction temperature.
What is the purpose of the ON/OFF pin (Pin 5) on the LM2575-12WT?
Pin 5 provides logic-level enable/disable control: applying <1.0V (typically 0V) enables regulation, while >2.2V (typically 5V) disables output and reduces quiescent current to <200µA. This allows system-level power sequencing, sleep mode entry, or fault-initiated shutdown without interrupting input supply.
Which inductor value is recommended for use with the LM2575-12WT?
A 330µH inductor is the standard recommendation for the LM2575-12WT, as validated in Micrel's typical application circuits. It balances ripple current (<30% of IOUT), saturation margin (>1.5× peak switch current), and physical size. Common part numbers include AIE 415-0926 and equivalent industry-standard shielded or toroidal types rated for ≥1.5A DC.
LM2575-12WT 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:
- 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:
- Through Hole
- Supplier Device Package:
- TO-220-5
LM2575-12WT FAQ
1.How can I place an order for LM2575-12WT through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575-12WT 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 LM2575-12WT reliable?
The price and inventory of LM2575-12WT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575-12WT is usually 5 days.
3.What payment methods are accepted for LM2575-12WT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575-12WT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575-12WT?
LM2575-12WT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575-12WT 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 LM2575-12WT?
For technical support, including LM2575-12WT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575-12WT requirements.
6.How does Aetrix verify that LM2575-12WT is sourced from the original manufacturer or authorized distributors?
All LM2575-12WT 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 LM2575-12WT meets industry standards.
7.What is the process for return or replacement of LM2575-12WT?
All LM2575-12WT units undergo pre-shipment inspection (PSI). If there is an issue with LM2575-12WT, 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 LM2575-12WT part is unused and in its original packaging.
Return procedure for LM2575-12WT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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