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Microchip Technology LM2575-12WU
- Part No.:
- LM2575-12WU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575-12WU.pdf
- Description:
- IC REG BUCK 12V 1A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,684
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Product details
Overview
LM2575-12WU 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 over line/load, internal current limiting, thermal shutdown, and <200µA standby current. It replaces linear regulators in industrial power supplies requiring high efficiency and minimal heatsink area.
For engineers reviewing the LM2575-12WU datasheet, LM2575-12WU pinout, LM2575-12WU application, or LM2575-12WU equivalent, key selection criteria include input voltage range (4–40V), guaranteed 1A output, TO-263 thermal performance (θJA = 45°C/W with 1 in² copper), and compatibility with standard off-the-shelf inductors.
Technical Context
The LM2575-12WU integrates a 52kHz oscillator, error amplifier, bandgap reference (1.23V), PWM comparator, and 1A NPN switch driver in a monolithic buck controller architecture. Its feedback loop uses external resistive divider for adjustable versions, but LM2575-12WU bypasses this via internal 12V regulation network.
Protection features include cycle-by-cycle current limiting (1.7–3.2A peak), thermal shutdown at ~150°C junction temperature, and ON/OFF control with logic-compatible input (VIH ≥ 2.2V, VIL ≤ 1.0V). Efficiency reaches 88% at VIN = 25V, IOUT = 1A, VOUT = 12V.
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 microcontrollers and analog circuitry without trimming. |
| Max Output Current | 1A continuous output supports mid-power applications like sensor modules or communication interfaces without external current boosting. |
| Input Voltage Range | 4V to 40V enables direct use with 12V/24V industrial buses, automotive batteries (with transient protection), and unregulated DC supplies. |
| Switching Frequency | 52kHz ±10% allows use of low-cost, high-saturation-current inductors (e.g., 330µH) while keeping EMI manageable in non-critical environments. |
| Efficiency | 88% at 25V input / 12V output / 1A load reduces power loss to ~1.4W, minimizing thermal design burden on PCB copper area. |
| Standby Current | <200µA when ON/OFF pin pulled high disables switching and halts regulation-critical for battery-backed systems needing ultra-low quiescent drain. |
| Thermal Resistance | θJA = 45°C/W (with 1 in² copper) enables 1A operation up to +85°C ambient without heatsink in typical layouts. |
Pinout & Package
LM2575-12WU uses a 5-pin TO-263 (D2Pak) surface-mount package with exposed thermal pad (TAB) connected to GND for enhanced heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Unregulated input supply connection | Accepts 4–40V DC; requires ≥100µF bulk capacitor near pin to suppress input ripple and switching transients. |
| 2 - OUTPUT | Switched output node driving external inductor | Connects to inductor's high-side; carries pulsed 1A current-layout must minimize trace inductance to reduce voltage spikes. |
| 3 - GND | Power ground reference | Common return for input cap, output cap, and feedback network; must tie directly to thermal pad for optimal thermal path. |
| 4 - FB | Feedback input (not used in fixed version) | Internally tied to 12V regulation network; left unconnected-no external resistor divider required. |
| 5 - ON/OFF | Logic-controlled enable/disable input | Drives internal comparator: ≥2.2V = ON, ≤1.0V = OFF; pulls to GND via 10kΩ for default-on operation. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12V output with ±3% tolerance | Eliminates external feedback resistors and calibration, reducing BOM count and layout sensitivity in cost-sensitive designs. |
| Integrated 1A NPN switch and driver | Removes need for external MOSFET and gate driver, simplifying design and improving reliability versus discrete buck controllers. |
| 52kHz fixed-frequency oscillator | Enables predictable EMI filtering and consistent inductor sizing across production batches without frequency drift compensation. |
| Cycle-by-cycle current limit (1.7–3.2A) | Prevents catastrophic failure during short-circuit or overload by clamping peak switch current before thermal runaway occurs. |
| Thermal shutdown with hysteresis | Shuts down at ~150°C junction and restarts after cooldown, protecting against sustained overloads without manual reset. |
Applications
| Industrial Power Supply | Automotive Subsystem Regulator |
|---|---|
|
Use Scenario: Converting 24V truck battery to stable 12V for telematics module logic and CAN transceiver. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated 12V rail with input transient tolerance up to 40V. Use Value: 88% efficiency minimizes heat in sealed enclosures; TO-263 thermal pad anchors to chassis ground for robust thermal management. |
Use Scenario: Generating 12V from vehicle's 12V battery (with cold-crank and load-dump protection) for infotainment display backlight drivers. IC Role / Device Role / Timing Role: High-reliability DC-DC converter with built-in current limit and thermal shutdown for harsh automotive environments. Use Value: Wide 4–40V input range accommodates battery dips to 6V and surges to 36V; ON/OFF pin enables ignition-synchronized power sequencing. |
| Programmable Logic Controller (PLC) I/O Module | Medical Sensor Interface Power |
|
Use Scenario: Providing regulated 12V to isolated analog input channels and digital I/O buffers in DIN-rail mounted PLCs. IC Role / Device Role / Timing Role: Compact, self-contained buck regulator replacing linear regulators to eliminate heatsinks in space-constrained modules. Use Value: 1A output supports multiple isolated DC-DC converters downstream; 52kHz frequency avoids interference with 50/60Hz AC sensing circuits. |
Use Scenario: Powering low-noise op-amps and ADCs in portable patient monitors where EMI and thermal noise must be minimized. IC Role / Device Role / Timing Role: Pre-regulator feeding low-dropout linear regulators to achieve clean 12V analog supply with low ripple. Use Value: Fixed 12V output eliminates feedback resistor errors; ±3% tolerance ensures consistent biasing across temperature for calibrated sensor front-ends. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575-12T | Same electrical specs, but in 5-pin TO-220 package with higher θJA = 65°C/W (no copper area assumed). | Requires mechanical mounting and heatsink for 1A continuous operation above +50°C ambient. | Select LM2575-12T only if through-hole assembly or forced-air cooling is available; LM2575-12WU preferred for SMT and compact thermal design. |
| LM2596-12 | Higher 150kHz switching frequency, 3A output rating, and improved efficiency (≥92%), but requires different inductor value and layout. | Better suited for higher-power or size-constrained designs where smaller magnetics and lower output ripple are critical. | Choose LM2596-12 when upgrading for >1A loads or tighter EMI requirements; LM2575-12WU remains optimal for legacy 52kHz-compliant designs and cost-sensitive volume production. |
Compared with LM2575-12T, LM2575-12WU delivers superior thermal performance in SMT layouts; compared with LM2596-12, it offers proven reliability and simpler magnetics selection at the cost of lower frequency and efficiency-making it ideal for industrial applications prioritizing long-term stability over peak performance.
Availability
LM2575-12WU is available at Aetrix Electronics and suitable for industrial automation, automotive subsystems, and medical instrumentation requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for LM2575-12WU 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 mixed-signal ICs before its acquisition by Microchip Technology in 2015.
The LM2575 series was designed as a drop-in, high-efficiency replacement for three-terminal linear regulators in industrial and embedded power supplies-emphasizing simplicity, thermal robustness, and minimal external component count.
FAQ
What is the maximum input voltage for LM2575-12WU?
The absolute maximum input voltage for LM2575-12WU is 45V, but the recommended operating range is 4V to 40V DC. Exceeding 40V risks violating the device's safe operating area, especially under high ambient temperatures or heavy load conditions. For automotive applications with load-dump transients, external TVS clamping is advised before the VIN pin to protect LM2575-12WU.
Does LM2575-12WU require an external feedback resistor network?
No, LM2575-12WU does not require external feedback resistors because it is a fixed-output variant-the 12V regulation is implemented internally. Pin 4 (FB) is internally connected to the reference network and must remain unconnected in standard operation. Adding external components to FB will disrupt regulation and is not supported.
How is thermal performance affected by PCB copper area for LM2575-12WU?
LM2575-12WU's thermal resistance θJA drops from 45°C/W (with 1 in² copper) to lower values with increased copper area. Doubling the copper area around the thermal pad can reduce θJA by ~10–15°C/W. The exposed TAB must be soldered to a solid GND plane-vias to inner-layer GND planes further improve heat spreading and allow reliable 1A operation up to +85°C ambient.
Can LM2575-12WU be used in negative-output (inverting) configurations?
Yes, LM2575-12WU can be configured as a negative-output buck-boost converter using standard inverting topology-though the output polarity becomes negative relative to input GND. This requires repositioning the inductor and diode, and the 12V internal reference no longer applies; output magnitude depends on duty cycle and component selection. Refer to Micrel Application Note AN-12 for validated schematics and stability guidelines.
What is the purpose of the ON/OFF pin on LM2575-12WU?
The ON/OFF pin (Pin 5) enables logic-level control of LM2575-12WU's switching operation: pulling it to GND (≤1.0V) activates regulation, while pulling it high (≥2.2V) places the device in standby mode with <200µA quiescent current. This feature supports power sequencing, battery-saving sleep modes, and system-level fault recovery-without requiring external MOSFETs or complex enable circuitry.
LM2575-12WU 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:
- 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
LM2575-12WU FAQ
1.How can I place an order for LM2575-12WU through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575-12WU 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 LM2575-12WU reliable?
The price and inventory of LM2575-12WU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575-12WU is usually 5 days.
3.What payment methods are accepted for LM2575-12WU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575-12WU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575-12WU?
LM2575-12WU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575-12WU 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 LM2575-12WU?
For technical support, including LM2575-12WU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575-12WU requirements.
6.How does Aetrix verify that LM2575-12WU is sourced from the original manufacturer or authorized distributors?
All LM2575-12WU 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 LM2575-12WU meets industry standards.
7.What is the process for return or replacement of LM2575-12WU?
All LM2575-12WU units undergo pre-shipment inspection (PSI). If there is an issue with LM2575-12WU, 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 LM2575-12WU part is unused and in its original packaging.
Return procedure for LM2575-12WU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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