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Microchip Technology MIC4576-3.3BU TR
- Part No.:
- MIC4576-3.3BU TR
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC4576-3.3BU TR.pdf
- Description:
- IC REG BUCK 3.3V 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,619
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Product details
Overview
MIC4576-3.3BU TR from Microchip Technology is a fixed-output 3.3V, 3A synchronous step-down (buck) switching regulator with 200 kHz fixed-frequency operation, ±3% output voltage tolerance over line/load/temperature, 4V–36V input range, and integrated thermal shutdown and cycle-by-cycle current limiting. It delivers stable 3.3V power for Intel Pentium™-class microprocessors and industrial embedded systems requiring high-efficiency DC-DC conversion.
For engineers reviewing the MIC4576-3.3BU TR datasheet, MIC4576-3.3BU TR pinout, MIC4576-3.3BU TR application, or MIC4576-3.3BU TR equivalent, key selection criteria include guaranteed 3A switch current, TO-263 (DDPAK) thermal performance (θJC = 2°C/W), shutdown current <200 µA, and compatibility with standard inductors at reduced size versus LM2576.
Technical Context
The MIC4576-3.3BU TR implements a BiCMOS buck topology with internal 3A NPN power switch, 1.23V bandgap reference, and fixed 200 kHz oscillator (±10% tolerance). Its error amplifier compares feedback against the internal 1.23V reference to generate variable-duty-cycle PWM via comparator-driven gate drive.
Thermal shutdown activates at TJ ≥ +150°C; overcurrent protection operates cycle-by-cycle with peak current limit of 4.2–7.9 A. The device requires no external frequency compensation and supports both enable/shutdown control (TTL-compatible SHDN pin) and fixed-output configuration with direct FB-to-VOUT connection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 3.3 V ±3% (guaranteed across –40°C to +85°C, 6V–36V VIN, 0.5–3A load) |
| Switch Current | Guaranteed 3 A continuous (supports 3A load without derating at TA ≤ +50°C with proper heatsinking) |
| Input Voltage Range | 4 V to 36 V (enables direct use with 12/24V industrial rails and automotive battery inputs) |
| Switching Frequency | 200 kHz ±10% (allows ~2× smaller output inductor vs. 52 kHz LM2576, reducing board area) |
| Efficiency | 72% typical at 3A load (enables >1W power delivery with <0.3W conduction loss at 12V input) |
| Shutdown Current | <200 µA typical (reduces system standby power in battery-backed applications) |
| Thermal Resistance | θJC = 2°C/W (enables high-power operation with minimal case-to-heatsink ΔT) |
Pinout & Package
Package: 5-Lead TO-263 (DDPAK), thermally enhanced surface-mount package with exposed tab (GND-connected) for low-thermal-resistance PCB mounting. Tab serves as primary heat path to copper pour.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Unregulated input supply | Accepts 4–36V DC; must be decoupled with ≥470 µF low-ESR capacitor near pin |
| SW (Pin 2) | Switch node output | Drives external inductor; connects to cathode of Schottky diode (e.g., MBR360) and inductor |
| GND / TAB (Pins 3 & Tab) | Power and signal ground | Tab is electrically connected to Pin 3; must be soldered to large PCB copper area for thermal management |
| FB (Pin 4) | Feedback input | Internally tied to 3.3V divider; connect directly to regulated output for fixed-voltage operation |
| SHDN (Pin 5) | Enable/disable control | TTL-compatible input; logic low (≤0.8V) enables regulator; logic high (≥2.4V) disables with <200 µA quiescent draw |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 200 kHz switching | Enables predictable EMI filtering and consistent inductor sizing-no external timing components required |
| ±3% output voltage accuracy | Meets tight regulation requirements for 3.3V digital logic rails without post-regulation LDOs |
| Integrated thermal shutdown | Automatically disables output when junction exceeds +150°C, preventing permanent damage during overload or poor heatsinking |
| Cycle-by-cycle current limiting | Protects internal switch and external components during short-circuit or startup inrush without latch-up |
| TO-263 (U) package | Provides 2°C/W junction-to-case thermal resistance-ideal for space-constrained industrial PCBs needing high power density |
Applications
| Intel Pentium™ Microprocessor Power | Industrial PLC I/O Module Supply |
|---|---|
Use Scenario: Providing clean, regulated 3.3V rail to legacy x86 CPU cores and associated support logic on embedded motherboard. IC Role / Device Role / Timing Role: Primary step-down regulator converting 12V or 24V backplane voltage to stable 3.3V at up to 3A continuous. Use Value: Eliminates need for discrete MOSFET+controller design; ±3% tolerance ensures reliable CPU boot and operation per Intel specifications. | Use Scenario: Generating isolated 3.3V supply for analog sensor interface circuitry and digital I/O drivers in programmable logic controller modules. IC Role / Device Role / Timing Role: High-reliability DC-DC converter operating from wide-input 12–36V industrial bus under temperature extremes. Use Value: 200 kHz switching reduces filter component size; thermal shutdown protects against field failures due to ambient overheating. |
| Battery-Powered Test Equipment | POS Terminal Power Management |
Use Scenario: Converting 9–18V Li-ion pack voltage to 3.3V for MCU, display, and communication ICs in portable diagnostic tools. IC Role / Device Role / Timing Role: Efficient buck regulator with ultra-low shutdown current (<200 µA) enabling multi-week standby life. Use Value: 72% efficiency at full load extends runtime; TO-263 package allows compact layout with minimal heatsink area. | Use Scenario: Delivering 3.3V to payment processing SoCs, secure elements, and touch controllers in retail point-of-sale terminals. IC Role / Device Role / Timing Role: Main 3.3V power source operating from 12V wall adapter or backup battery with fast transient response. Use Value: Guaranteed 3A capability supports burst-mode processing loads; fixed 3.3V output eliminates resistor-divider calibration overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC4576-3.3WT | Same IC die, but in TO-220 through-hole package (θJA = 65°C/W vs. 65°C/W for U); no tape-and-reel option | Preferred for prototyping or low-volume assembly where manual soldering or socketing is used | Select MIC4576-3.3WT if board assembly uses through-hole process or requires easier thermal testing with clip-on heatsink |
| LM2576-3.3 | 52 kHz switching, larger inductor requirement, ±4% output tolerance, no integrated shutdown pin, TO-220 only | Suitable for cost-sensitive, non-space-constrained designs where EMI filtering is less critical | Choose LM2576-3.3 only if legacy design reuse or lower-frequency EMI compliance is mandatory; not drop-in compatible |
Compared with MIC4576-3.3WT and LM2576-3.3, the MIC4576-3.3BU TR offers superior power density (TO-263), tighter regulation (±3% vs. ±4%), and built-in shutdown control-making it optimal for automated SMT production of compact industrial electronics.
Availability
MIC4576-3.3BU TR is available at Aetrix Electronics and suitable for industrial PLCs, embedded microprocessor power supplies, battery-powered test equipment, POS terminals, and telecom infrastructure requiring stable component supply with long lifecycle assurance.
Supply support for MIC4576-3.3BU 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
Microchip Technology is a global provider of microcontrollers, analog devices, and power management ICs, serving industrial, automotive, and communications markets with high-reliability semiconductor solutions.
The MIC4576 product line delivers easy-to-use, high-current buck regulators targeting cost-sensitive yet performance-demanding applications such as microprocessor core power, industrial power supplies, and battery-based systems requiring wide-input operation and robust protection.
FAQ
What is the maximum input voltage rating for the MIC4576-3.3BU TR?
The MIC4576-3.3BU TR has an absolute maximum input voltage rating of +40V, with recommended continuous operation up to +36V. Exceeding +36V may trigger internal protection or cause reliability degradation. The device is designed for industrial 12V/24V rails and automotive battery inputs with transient suppression.
Does the MIC4576-3.3BU TR require external compensation components?
No, the MIC4576-3.3BU TR features fully internal frequency compensation. No external capacitors or resistors are needed for loop stability-only input/output capacitors, inductor, and Schottky diode are required for basic operation, simplifying design and reducing BOM count.
How does the SHDN pin function on the MIC4576-3.3BU TR?
The SHDN pin on the MIC4576-3.3BU TR is TTL-compatible: a logic low (≤0.8V) enables regulation, while a logic high (≥2.4V) places the device in shutdown mode, reducing quiescent current to <200 µA. If unused, SHDN must be grounded to ensure reliable startup.
Can the MIC4576-3.3BU TR be used in negative-output (inverting) configurations?
Yes-the MIC4576-3.3BU TR supports positive-to-negative (inverting buck-boost) topologies per Microchip Application Note AN14. In this mode, it generates regulated negative output from a positive input, useful for dual-rail analog circuits, though output current capability is reduced versus standard buck operation.
What thermal performance can be expected from the MIC4576-3.3BU TR in a typical PCB layout?
In a standard 4-layer PCB with 2 oz copper and ≥4 cm² GND pour under the TO-263 tab, the MIC4576-3.3BU TR achieves θJA ≈ 40°C/W. With forced air or heatsink, junction temperature remains below +100°C at 3A load and +50°C ambient-well within its –40°C to +85°C operating range.
MIC4576-3.3BU 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:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- Frequency - Switching:
- 200kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263-5
MIC4576-3.3BU TR FAQ
1.How can I place an order for MIC4576-3.3BU TR through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4576-3.3BU 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 MIC4576-3.3BU TR reliable?
The price and inventory of MIC4576-3.3BU TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4576-3.3BU TR is usually 5 days.
3.What payment methods are accepted for MIC4576-3.3BU TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4576-3.3BU TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4576-3.3BU TR?
MIC4576-3.3BU TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4576-3.3BU 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 MIC4576-3.3BU TR?
For technical support, including MIC4576-3.3BU TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4576-3.3BU TR requirements.
6.How does Aetrix verify that MIC4576-3.3BU TR is sourced from the original manufacturer or authorized distributors?
All MIC4576-3.3BU 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 MIC4576-3.3BU TR meets industry standards.
7.What is the process for return or replacement of MIC4576-3.3BU TR?
All MIC4576-3.3BU TR units undergo pre-shipment inspection (PSI). If there is an issue with MIC4576-3.3BU 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 MIC4576-3.3BU TR part is unused and in its original packaging.
Return procedure for MIC4576-3.3BU TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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