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Microchip Technology LM2575-3.3BN
- Part No.:
- LM2575-3.3BN
- Manufacturer:
- Microchip Technology
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2575-3.3BN.pdf
- Description:
- IC REG BUCK 3.3V 1A 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,009
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Product details
Overview
LM2575-3.3BN from Micrel is a monolithic 3.3V fixed-output buck switching regulator delivering up to 1A output current with ±3% output voltage tolerance, 52kHz fixed-frequency operation, and input voltage range of 4V to 40V. It integrates internal frequency compensation, cycle-by-cycle current limiting, thermal shutdown, and ON/OFF control - used in embedded power supplies requiring compact, high-efficiency DC-DC conversion.
For engineers reviewing the LM2575-3.3BN datasheet, LM2575-3.3BN pinout, LM2575-3.3BN application, or LM2575-3.3BN equivalent, key selection considerations include guaranteed 1A load capability, TO-220-compatible 16-pin DIP package, 75% typical efficiency at 1A/12VIN, and compatibility with standard off-the-shelf inductors for rapid design implementation.
Technical Context
The LM2575-3.3BN implements a fixed-frequency (52kHz) PWM buck topology with an internal 1A NPN switch, bandgap reference (1.23V), and error amplifier. Its feedback loop is internally configured for 3.3V regulation via trimmed resistive divider, eliminating external resistor networks required by adjustable versions.
Protection features include thermal shutdown triggered at ~150°C junction temperature and peak-current limiting set at 1.7A (min) to 3.2A (max), ensuring safe operation under overload or short-circuit conditions without external circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±3% over full operating range - ensures stable logic supply for 3.3V microcontrollers and FPGAs without post-regulation. |
| Max Output Current | 1A continuous - supports single-rail digital subsystems including ARM Cortex-M series and industrial I/O modules. |
| Input Voltage Range | 4V to 40V - enables direct use with 12V/24V industrial buses, automotive battery inputs (with transient protection), and unregulated wall adapters. |
| Switching Frequency | 52kHz ±10% - allows use of low-cost, high-saturation-current toroidal inductors (e.g., 330µH) while minimizing EMI filtering complexity. |
| Efficiency | 75% typical at VIN=12V, IOUT=1A - reduces thermal load vs. linear regulators, often eliminating need for heatsinks in ambient ≤50°C. |
| Standby Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-backed systems and remote sensors. |
| Thermal Resistance | θJA = 85°C/W (16-pin DIP) - defines maximum power dissipation (≈1.4W) before thermal shutdown at 85°C ambient. |
Pinout & Package
LM2575-3.3BN is supplied in a 16-pin plastic DIP package with exposed thermal pad connected to Pin 3 (GND). Pin 1 is VIN, Pin 2 is OUTPUT, Pin 3 is GND, Pin 4 is FEEDBACK (internally tied to 3.3V divider), Pin 5 is ON/OFF - all other pins are NC or internal power/ground connections.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Main power input | Accepts 4–40V unregulated DC; requires ≥100µF bulk capacitance close to pin for stability and EMI suppression. |
| 2 - OUTPUT | Switched output node | Drives external catch diode and inductor; high dI/dt path requiring short, wide PCB traces and local ceramic bypassing. |
| 3 - GND | Power and signal ground | Common return for input cap, output cap, and feedback network; must be low-impedance single-point connection to minimize noise coupling. |
| 4 - FB | Feedback input | Internally connected to precision 3.3V divider; no external components required - distinguishes fixed from adjustable variants. |
| 5 - ON/OFF | Enable/disable control | Logic-high (>2.2V) enables regulation; logic-low (<1.0V) disables output and reduces quiescent current to <200µA. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 1A NPN switch | Eliminates need for external MOSFET and gate driver - reduces BOM count and layout area in space-constrained designs. |
| Internal frequency compensation | Enables stable operation with only 4 external components (input cap, output cap, inductor, catch diode) - accelerates prototyping. |
| Thermal shutdown + current limit | Provides autonomous fault recovery without external sensing or protection ICs - improves system reliability in harsh environments. |
| Standard inductor compatibility | Optimized for widely available 330µH, 2A+ saturation current inductors (e.g., AIE 415-0926) - avoids custom magnetics procurement delays. |
| ON/OFF logic control | Supports system-level power sequencing and standby modes via microcontroller GPIO - simplifies firmware-controlled power management. |
Applications
| Industrial PLC I/O Module | Automotive Body Control Unit |
|---|---|
Use Scenario: Powering isolated 3.3V digital logic and CAN transceivers in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Primary 3.3V buck regulator converting 24V rail to clean logic supply; operates continuously at 1A load with minimal thermal rise. Use Value: Replaces inefficient 78L33 linear regulator, reducing board temperature by >25°C and enabling conformal coating without derating. | Use Scenario: Supplying 3.3V to microcontroller, EEPROM, and LIN transceiver in door module electronics. IC Role / Device Role / Timing Role: Input-stage DC-DC converter accepting 9–16V battery input; withstands load dump transients when paired with TVS diode. Use Value: Maintains regulation down to 4V input, supporting cold-crank operation; ON/OFF pin synchronized with vehicle ignition state. |
| Medical Sensor Hub | Point-of-Sale Terminal |
Use Scenario: Generating 3.3V for low-noise analog front-end and Bluetooth LE radio in portable patient monitors. IC Role / Device Role / Timing Role: Fixed-output buck regulator feeding LDO post-regulator; 52kHz switching frequency avoids interference with 1–10kHz physiological signal bands. Use Value: Achieves 75% efficiency at 500mA, extending battery life vs. linear solution while meeting IEC 60601-1 creepage requirements via DIP package spacing. | Use Scenario: Providing 3.3V to ARM-based payment processor, display driver, and contactless reader IC in retail terminals. IC Role / Device Role / Timing Role: Main system regulator converting 12V adapter input; handles dynamic 100–1000mA load steps during NFC transaction bursts. Use Value: Load transient response settles within 100µs (±100mV), preventing processor brownouts during secure element communication. |
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; packaged in 5-pin TO-220 with lower θJA (65°C/W) and integrated heat sink tab. | Better thermal performance in high-ambient or sealed enclosures; requires through-hole mounting and mechanical fastening. | Select LM2575-3.3T when board-level thermal resistance exceeds 40°C/W or ambient exceeds 60°C. |
| LM2596-3.3 | Higher 150kHz switching frequency, 3A rating, ±2% output tolerance, and improved efficiency (≥85% at 1A). | Enables smaller inductors/caps but requires tighter layout for EMI control; not pin-compatible with LM2575-3.3BN. | Choose LM2596-3.3 for new designs needing higher efficiency or power headroom; redesign PCB and filter components required. |
Compared with LM2575-3.3T, the LM2575-3.3BN offers identical regulation accuracy and protection but trades thermal performance for DIP-mounting flexibility and legacy footprint compatibility. Against LM2596-3.3, it provides proven robustness in noisy industrial settings at lower cost, though with larger passive components and reduced efficiency.
Availability
LM2575-3.3BN is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical sensor applications requiring stable component supply across extended product lifecycles.
Supply support for LM2575-3.3BN 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.
The LM2575 series was designed as a drop-in high-efficiency replacement for three-terminal linear regulators in cost-sensitive, thermally constrained DC-DC applications - targeting industrial, automotive, and consumer power systems.
FAQ
What is the maximum input voltage rating for LM2575-3.3BN?
The absolute maximum input voltage for LM2575-3.3BN is 45V, but the recommended operating range is 4V to 40V. Exceeding 40V may trigger internal protection or reduce long-term reliability. The device maintains regulation across this full range, making it suitable for 24V industrial rails with transient margin.
Does LM2575-3.3BN require external feedback resistors?
No, LM2575-3.3BN does not require external feedback resistors. It is a fixed-output variant with internal resistor divider configured for 3.3V regulation; Pin 4 (FB) is internally connected and must remain unconnected to external components per datasheet guidance.
Can LM2575-3.3BN be used in negative-output configurations?
Yes, LM2575-3.3BN can be used in inverting buck-boost topology to generate negative voltages, as documented in the "Typical Applications" section of its datasheet. This requires reconfiguring the inductor and diode placement, with output referenced to VIN instead of GND - output polarity and regulation accuracy remain valid.
What is the thermal shutdown threshold for LM2575-3.3BN?
The LM2575-3.3BN activates thermal shutdown at approximately 150°C junction temperature, as specified in Absolute Maximum Ratings. Recovery occurs automatically once junction temperature falls below ~135°C, providing self-protecting operation during sustained overload or inadequate heatsinking.
Is LM2575-3.3BN RoHS compliant?
No, LM2575-3.3BN is not RoHS compliant. Per the Ordering Information table, "Contact Factory" is listed under Pb-Free/RoHS Compliant column, indicating leaded packaging. For RoHS-compliant alternatives, consider LM2575-3.3WU (TO-263) or LM2575-3.3YWM (SOIC), both marked "RoHS Compliant" in official documentation.
LM2575-3.3BN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- 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):
- 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:
- Through Hole
- Supplier Device Package:
- 16-DIP
LM2575-3.3BN FAQ
1.How can I place an order for LM2575-3.3BN through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575-3.3BN 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 LM2575-3.3BN reliable?
The price and inventory of LM2575-3.3BN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575-3.3BN is usually 5 days.
3.What payment methods are accepted for LM2575-3.3BN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575-3.3BN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575-3.3BN?
LM2575-3.3BN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575-3.3BN 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 LM2575-3.3BN?
For technical support, including LM2575-3.3BN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575-3.3BN requirements.
6.How does Aetrix verify that LM2575-3.3BN is sourced from the original manufacturer or authorized distributors?
All LM2575-3.3BN 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 LM2575-3.3BN meets industry standards.
7.What is the process for return or replacement of LM2575-3.3BN?
All LM2575-3.3BN units undergo pre-shipment inspection (PSI). If there is an issue with LM2575-3.3BN, 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 LM2575-3.3BN part is unused and in its original packaging.
Return procedure for LM2575-3.3BN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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