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Microchip Technology LM2575-3.3WU-TR
- Part No.:
- LM2575-3.3WU-TR
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575-3.3WU-TR.pdf
- Description:
- IC REG BUCK 3.3V 1A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:308
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Product details
Overview
LM2575-3.3WU-TR from Micrel is a fixed-output 3.3V, 1A step-down (buck) switching regulator in TO-263 package, featuring 52kHz fixed-frequency operation, ±3% output voltage tolerance over line/load, thermal shutdown, and cycle-by-cycle current limiting - used in on-card DC/DC conversion for industrial power rails.
For engineers reviewing the LM2575-3.3WU-TR datasheet, LM2575-3.3WU-TR pinout, LM2575-3.3WU-TR application, or LM2575-3.3WU-TR equivalent, key selection criteria include input voltage range (4–40V), guaranteed 1A output, standby current <200µA, TO-263 thermal performance (θJA = 45°C/W with 4 in² copper), and compatibility with standard off-the-shelf inductors.
Technical Context
The LM2575-3.3WU-TR integrates a 52kHz oscillator, error amplifier, bandgap reference (1.23V), PWM comparator, and 1A NPN switch driver in monolithic form. Its internal feedback network fixes output at 3.3V, eliminating external resistor dividers required by adjustable variants.
It employs cycle-by-cycle current limiting and thermal shutdown for fault protection, and uses an external Schottky catch diode, inductor, and input/output capacitors to complete the buck topology - no external frequency compensation needed due to built-in compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±3% over 0.2–1A load and 8–40V input - ensures stable logic rail generation without trimming. |
| Max Output Current | 1A continuous - supports microcontroller cores, FPGAs, and peripheral ICs requiring moderate power. |
| Input Voltage Range | 4V to 40V - accommodates wide-input industrial supplies, automotive battery systems (12V/24V), and unregulated adapters. |
| Oscillator Frequency | 52kHz ±10% - enables use of low-cost, high-saturation-current inductors (e.g., 330µH) and reduces EMI filtering complexity. |
| Efficiency | 75% at 12VIN/3.3VOUT/1A - significantly reduces heat dissipation vs. linear regulators, often eliminating heatsinks. |
| Standby Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-backed or energy-conscious systems. |
| Thermal Resistance | θJA = 45°C/W with 4 in² PCB copper - allows reliable 1A operation at +85°C ambient without forced air or heatsink. |
Pinout & Package
LM2575-3.3WU-TR uses a 5-pin TO-263 (also known as D2PAK) surface-mount package with exposed tab for thermal conduction. Pin 1 is VIN, Pin 2 is OUTPUT, Pin 3 is GND, Pin 4 is FEEDBACK (internally connected to fixed 3.3V divider), and Pin 5 is ON/OFF.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Unregulated input supply connection | Accepts 4–40V DC; requires ≥100µF input capacitor near pin for stability and ripple suppression. |
| 2 (OUTPUT) | Switching node and regulated output | Drives external inductor and catch diode; connects to output capacitor (≥330µF) for low-ripple 3.3V rail. |
| 3 (GND) | Power and signal ground reference | Must be low-impedance single-point ground; ties to exposed tab for thermal path to PCB copper. |
| 4 (FEEDBACK) | Internal voltage sense point | Internally tied to 3.3V divider - not user-accessible; unused in fixed versions but must remain unconnected. |
| 5 (ON/OFF) | Logic-controlled enable/disable input | Active-high: ≥2.2V enables regulator; ≤1.0V disables with <200µA quiescent draw - supports system-level power sequencing. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3V output | Eliminates external feedback resistors, reducing BOM count and layout sensitivity while guaranteeing ±3% accuracy across temperature and load. |
| Integrated 1A NPN switch | Removes need for external MOSFET or transistor, simplifying design and improving reliability in compact space-constrained applications. |
| 52kHz fixed-frequency oscillator | Enables predictable EMI profile and consistent inductor sizing - avoids variable-frequency jitter and simplifies filter design. |
| Thermal shutdown + current limit | Provides autonomous fault recovery: halts switching during overtemperature or overload, then auto-restarts when safe - no external protection circuitry required. |
| Low external component count | Requires only four external parts (input cap, inductor, catch diode, output cap) - accelerates prototyping and reduces PCB area vs. controller-based solutions. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
Use Scenario: Providing isolated 3.3V logic supply from 12V/24V vehicle battery in BCU modules with vibration, temperature, and EMI constraints. IC Role / Device Role / Timing Role: Primary buck regulator generating clean 3.3V rail for MCU, CAN transceivers, and sensor interfaces. Use Value: Delivers 1A at 75% efficiency with TO-263 thermal performance enabling convection-only cooling in sealed enclosures. | Use Scenario: On-board 3.3V supply for FPGA configuration and peripheral logic in programmable logic controller backplanes. IC Role / Device Role / Timing Role: Fixed-output DC/DC converter replacing linear regulators to eliminate heatsinks and reduce board space. Use Value: ±3% output tolerance ensures reliable operation of 3.3V I/O standards (e.g., LVCMOS) across –40°C to +85°C. |
| Medical Diagnostic Handheld Device | Point-of-Sale (POS) Terminal Power |
Use Scenario: Battery-powered handheld ultrasound or glucose meter requiring efficient 3.3V rail from 2-cell Li-ion (6–8.4V) or 9V alkaline. IC Role / Device Role / Timing Role: Main step-down regulator enabling low-quiescent sleep mode via ON/OFF pin control. Use Value: Standby current <200µA extends battery life during idle periods while maintaining fast wake-up capability. | Use Scenario: Compact retail terminal with integrated printer, display, and barcode scanner needing robust 3.3V rail from 12V wall adapter. IC Role / Device Role / Timing Role: High-reliability buck converter supporting mixed-signal loads with transient immunity. Use Value: Cycle-by-cycle current limiting prevents latch-up during printer motor startup surges or display backlight turn-on. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575-3.3T | Same electrical specs, but in 5-pin TO-220 through-hole package with θJA = 65°C/W (no heatsink) or 45°C/W (with 4 in² copper). | TO-220 requires manual assembly or wave soldering; less suitable for high-density SMT production. | Select LM2575-3.3T only if through-hole mounting, vertical heatsinking, or legacy board compatibility is required. |
| LM2576-3.3WU-TR | Higher efficiency (~85% at 12VIN/3.3VOUT/1A), lower quiescent current (50µA), and improved line regulation (±1.5%), but same pinout and footprint. | Drop-in replacement with enhanced performance; requires verification of inductor saturation current (higher peak current). | LM2576-3.3WU-TR offers measurable efficiency and thermal improvement while maintaining identical layout - recommended for new designs where margin matters. |
Compared with LM2575-3.3T, the LM2575-3.3WU-TR provides superior thermal performance in SMT layouts; compared with LM2576-3.3WU-TR, it trades ~10% efficiency and higher standby current for proven long-term reliability and broader distributor stock availability.
Availability
LM2575-3.3WU-TR is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical portable devices requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for LM2575-3.3WU-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 analog and mixed-signal semiconductor company headquartered in San Jose, CA, acquired by Microchip Technology in 2015. It specialized in power management, timing, and interface ICs.
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 and reliability outweigh advanced features.
FAQ
What is the maximum input voltage rating for LM2575-3.3WU-TR?
The absolute maximum input voltage for LM2575-3.3WU-TR is 45V, but the recommended operating range is 4V to 40V DC. Exceeding 40V may trigger internal protection or degrade long-term reliability. The device maintains regulation down to 4V input, making it suitable for brownout conditions in 5V or 12V systems.
Does LM2575-3.3WU-TR require an external feedback resistor network?
No, LM2575-3.3WU-TR does not require external feedback resistors. It is a fixed-output variant with internal resistor divider set to 3.3V; the FEEDBACK pin (Pin 4) is internally connected and must be left unconnected in PCB layout. This eliminates tuning errors and improves production consistency.
Can LM2575-3.3WU-TR be used in negative-output (inverting) configurations?
Yes, LM2575-3.3WU-TR can be configured as a positive-to-negative inverting buck-boost converter per Micrel Application Note AN-8. In this topology, the device generates a regulated –3.3V output using the same external components, though efficiency drops to ~65–70% and output current capability is reduced to ~0.7A due to duty-cycle limitations.
What thermal derating applies to LM2575-3.3WU-TR at +85°C ambient?
At +85°C ambient with 4 in² of 2-oz copper on the PCB, LM2575-3.3WU-TR delivers full 1A output continuously. Derating begins above +85°C: output current reduces linearly to ~0.6A at +105°C junction (TJ = TA + θJA × PD), with thermal shutdown activating at 150°C junction to prevent damage.
Is LM2575-3.3WU-TR RoHS compliant?
Yes, LM2575-3.3WU-TR is RoHS compliant with the "high-melting solder" exemption per the Micrel ordering information table. It contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE, and meets EU Directive 2011/65/EU requirements for commercial and industrial applications.
LM2575-3.3WU-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:
- 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):
- 3.3V
- 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
LM2575-3.3WU-TR FAQ
1.How can I place an order for LM2575-3.3WU-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575-3.3WU-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 LM2575-3.3WU-TR reliable?
The price and inventory of LM2575-3.3WU-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575-3.3WU-TR is usually 5 days.
3.What payment methods are accepted for LM2575-3.3WU-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575-3.3WU-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575-3.3WU-TR?
LM2575-3.3WU-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575-3.3WU-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 LM2575-3.3WU-TR?
For technical support, including LM2575-3.3WU-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575-3.3WU-TR requirements.
6.How does Aetrix verify that LM2575-3.3WU-TR is sourced from the original manufacturer or authorized distributors?
All LM2575-3.3WU-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 LM2575-3.3WU-TR meets industry standards.
7.What is the process for return or replacement of LM2575-3.3WU-TR?
All LM2575-3.3WU-TR units undergo pre-shipment inspection (PSI). If there is an issue with LM2575-3.3WU-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 LM2575-3.3WU-TR part is unused and in its original packaging.
Return procedure for LM2575-3.3WU-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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