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Microchip Technology LM2576-5.0BU
- Part No.:
- LM2576-5.0BU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2576-5.0BU.pdf
- Description:
- IC REG BUCK 5V 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,273
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Product details
Overview
LM2576-5.0BU from Micrel is a fixed-output 5V, 3A step-down (buck) switching regulator in TO-263-5 package, featuring 52kHz fixed-frequency operation, ±3% output voltage tolerance over line/load/temperature, and integrated thermal shutdown and cycle-by-cycle current limiting. It replaces linear regulators in medium-power DC-DC conversion for industrial power supplies and embedded systems.
For engineers reviewing the LM2576-5.0BU datasheet, LM2576-5.0BU pinout, LM2576-5.0BU application, or LM2576-5.0BU equivalent, key selection considerations include input voltage range (4–40V), guaranteed 3A output capability, standby current <200µA, and compatibility with standard off-the-shelf inductors - all critical for reliable, heat-efficient buck converter design.
Technical Context
The LM2576-5.0BU integrates a 3A NPN switch, 52kHz oscillator, error amplifier with 1.23V reference, and PWM comparator in a monolithic buck controller architecture. Its feedback loop uses internal compensation, eliminating external compensation components.
It operates in continuous conduction mode with fixed frequency, supports ON/OFF control via pin 5 (logic-compatible with 0V/5V levels), and delivers regulated 5V output without external resistor dividers - unlike adjustable variants. Protection includes thermal shutdown and peak-current limiting at 4.2–7.5A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±3% over –40°C to +85°C, 0.5–3A load, 8–40V input - ensures stable rail for microcontrollers and logic without trimming. |
| Max Output Current | 3A DC - supports medium-power loads like sensors, displays, and peripheral interfaces without external current boosting. |
| Input Voltage Range | 4V to 40V - accommodates wide-input industrial, automotive, and battery-derived supplies (e.g., 12V/24V nominal systems). |
| Switching Frequency | 52kHz ±10% - enables use of low-cost, high-saturation-current inductors (e.g., 330µH) and simplifies EMI filtering. |
| Efficiency | 82% at VIN=12V, IOUT=3A - reduces thermal load vs. linear regulators; eliminates need for heatsink in many applications. |
| Standby Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-backed or energy-conscious systems. |
| Protection Features | Thermal shutdown + cycle-by-cycle current limit - prevents damage during overload, short-circuit, or ambient overheating. |
Pinout & Package
Package: TO-263-5 (surface-mount, thermally enhanced D²PAK). Exposed tab is electrically connected to GND and serves as primary thermal path to PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Unregulated input supply connection | Accepts 4–40V DC; requires local 100µF input capacitor to suppress ripple and transient spikes. |
| 2 - OUTPUT | Regulated 5V output node | Drives load directly; connects to output inductor and catch diode anode; must be decoupled with ≥330µF capacitor. |
| 3 - GND | Power and signal ground reference | Common return for input, output, feedback, and ON/OFF circuits; ties to exposed thermal pad for thermal management. |
| 4 - FEEDBACK | Internal voltage regulation sense point | Internally tied to 5V output - no external resistors required; unused in fixed-output configuration. |
| 5 - ON/OFF | Enable/disable control input | Logic-low (≤0.8V) enables regulator; logic-high (≥2.2V) disables output and reduces quiescent current to <200µA. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 5V output | Eliminates external feedback resistors, reducing BOM count and layout sensitivity versus adjustable regulators. |
| Integrated thermal protection | Automatically shuts down above ~150°C junction temperature and recovers after cooldown - no external circuitry needed. |
| Low-component-count design | Requires only four external parts: input cap, output cap, inductor, and Schottky catch diode - accelerates prototyping. |
| Standard inductor compatibility | Optimized for widely available 330µH, 4A+ saturation current inductors - avoids custom magnetics procurement delays. |
| Robust ON/OFF control | Supports TTL/CMOS-compatible enable signals with sub-10µA leakage in both states - ideal for MCU-driven power sequencing. |
Applications
| Industrial Power Supply | Embedded System Rail Generation |
|---|---|
|
Use Scenario: Converting 24V DC bus to stable 5V for PLC I/O modules and sensor interfaces. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated, efficient, and thermally robust 5V rail. Use Value: Delivers full 3A at 82% efficiency with no heatsink required, reducing board area and system cost. |
Use Scenario: Generating 5V for ARM Cortex-M microcontrollers, USB peripherals, and display drivers in edge devices. IC Role / Device Role / Timing Role: Main system power IC enabling low-quiescent sleep modes via ON/OFF pin control. Use Value: Standby current <200µA extends battery life; fixed 5V output ensures consistent logic-level compliance. |
| Automotive Aftermarket Electronics | Test Equipment Power Module |
|
Use Scenario: Regulating variable vehicle battery voltage (9–16V) to clean 5V for infotainment control boards. IC Role / Device Role / Timing Role: Input-tolerant buck converter handling cold-crank (4V) and load-dump transients. Use Value: 40V absolute max input rating and built-in current limiting protect against automotive electrical faults. |
Use Scenario: Providing calibrated 5V output in portable multimeters and handheld analyzers with battery backup. IC Role / Device Role / Timing Role: Precision-regulated power source with ±3% output accuracy across temperature and load. Use Value: Guaranteed 5.0V ±3% tolerance ensures measurement reference stability without calibration drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576-5.0WU | Same electrical specs; RoHS-compliant variant with "hot-melting solder" exemption - identical TO-263-5 package and pinout. | No functional difference; selected when RoHS documentation or exemption tracking is required for compliance reporting. | Choose LM2576-5.0WU if formal RoHS certification with exemption clause is mandated by OEM procurement policy. |
| LM2596-5.0 | Higher 150kHz switching frequency, lower 3A max current, different pinout (TO-220-5 only), and ±4% output tolerance. | Enables smaller inductors/caps but requires PCB redesign; less suitable for high-temperature industrial environments due to lower thermal margin. | Consider LM2596-5.0 only when board space is constrained and 150kHz operation is acceptable - not drop-in compatible. |
Compared with LM2576-5.0WU, the LM2576-5.0BU offers identical performance and footprint but lacks formal RoHS exemption documentation; versus LM2596-5.0, it provides superior thermal robustness, tighter output tolerance, and proven reliability in legacy industrial designs - though at the cost of larger passive components.
Availability
LM2576-5.0BU is available at Aetrix Electronics and suitable for industrial power supplies, embedded system rail generation, and automotive aftermarket electronics requiring stable component supply and long-term obsolescence management.
Supply support for LM2576-5.0BU 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 power semiconductor manufacturer acquired by Microchip Technology in 2015; known for high-reliability DC-DC regulators and timing solutions.
The LM2576 series was designed as a rugged, low-component-count replacement for linear regulators in industrial and embedded power applications - prioritizing thermal resilience, fault protection, and ease of implementation over ultra-high frequency or digital control.
FAQ
What is the maximum input voltage rating for the LM2576-5.0BU?
The LM2576-5.0BU has an absolute maximum input voltage of 45V, with recommended operating range from 4V to 40V. This allows safe operation across automotive battery transients (e.g., cold-crank at 4V, load dump up to 40V) and industrial 24V/48V systems. Exceeding 45V risks permanent damage to the internal switch.
Does the LM2576-5.0BU require external feedback resistors to set its output voltage?
No, the LM2576-5.0BU does not require external feedback resistors. As a fixed-output variant, its internal feedback network is factory-trimmed to deliver 5.0V ±3%. Pin 4 (FEEDBACK) is internally connected to the output and must remain unconnected - adding external resistors would disrupt regulation and is not supported.
Can the LM2576-5.0BU be used in a negative-output (inverting) configuration?
Yes, the LM2576-5.0BU can be configured as a negative-output buck-boost converter per Micrel Application Note AN-11. In this topology, the IC regulates a negative rail (e.g., –5V) using the same external components, leveraging its ability to sink current at the OUTPUT pin. However, output polarity and grounding constraints differ significantly from standard buck operation.
What thermal management is required for the LM2576-5.0BU at full 3A load?
At 3A and 12V input, the LM2576-5.0BU dissipates ~2.1W. With θJA ≈ 45°C/W (TO-263 on 1 in² copper), junction rise is ~95°C above ambient - well within the 125°C max operating limit. A minimum 1 in² thermal pad connected to the exposed tab is sufficient; no heatsink is required under typical conditions.
Is the LM2576-5.0BU pin-compatible with the LM2576-5.0BT (TO-220 version)?
No, the LM2576-5.0BU (TO-263-5) and LM2576-5.0BT (TO-220-5) share identical pin functions and numbering (VIN, OUTPUT, GND, FEEDBACK, ON/OFF), but their mechanical footprints and thermal pad configurations differ. While electrical interconnection is identical, PCB layout must be redesigned to accommodate the surface-mount TO-263 package versus through-hole TO-220.
LM2576-5.0BU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- 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):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- 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
LM2576-5.0BU FAQ
1.How can I place an order for LM2576-5.0BU through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576-5.0BU 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 LM2576-5.0BU reliable?
The price and inventory of LM2576-5.0BU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576-5.0BU is usually 5 days.
3.What payment methods are accepted for LM2576-5.0BU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576-5.0BU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576-5.0BU?
LM2576-5.0BU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576-5.0BU 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 LM2576-5.0BU?
For technical support, including LM2576-5.0BU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576-5.0BU requirements.
6.How does Aetrix verify that LM2576-5.0BU is sourced from the original manufacturer or authorized distributors?
All LM2576-5.0BU 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 LM2576-5.0BU meets industry standards.
7.What is the process for return or replacement of LM2576-5.0BU?
All LM2576-5.0BU units undergo pre-shipment inspection (PSI). If there is an issue with LM2576-5.0BU, 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 LM2576-5.0BU part is unused and in its original packaging.
Return procedure for LM2576-5.0BU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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