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Microchip Technology MIC4576WU
- Part No.:
- MIC4576WU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC4576WU.pdf
- Description:
- IC REG BUCK ADJ 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:185
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Product details
Overview
MIC4576WU from Microchip Technology is a 200 kHz fixed-frequency, adjustable-output buck switching regulator in TO-263 (DDPAK) package, delivering up to 3A output current with ±2% feedback voltage accuracy across 4V–36V input and 1.23V–33V output ranges. It integrates thermal shutdown, cycle-by-cycle overcurrent protection, and <200 µA shutdown current-used in industrial power supplies and battery chargers requiring compact, high-efficiency DC/DC conversion.
For engineers reviewing the MIC4576WU datasheet, MIC4576WU pinout, MIC4576WU application, or MIC4576WU equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts, and supply-chain support for production-grade implementation.
Technical Context
The MIC4576WU implements a BiCMOS-based synchronous-buck architecture with internal 3A NPN switch, 1.23V bandgap reference, and 200 kHz oscillator with ±10% tolerance. Its error amplifier compares FB voltage against the 1.23V reference to control duty cycle via PWM comparator against a sawtooth waveform.
It operates across –40°C to +85°C junction temperature, supports external resistive feedback divider for output adjustment, and features TTL-compatible SHDN logic with 1.2V turn-on and 1.4V turn-off thresholds-enabling precise enable/disable sequencing in multi-rail systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 200 kHz ±10% - enables use of smaller inductors (≈50% size vs LM2576) and reduces output filter footprint. |
| Output Current | Guaranteed 3A continuous - supports high-power loads without external current boosting. |
| Input Voltage Range | 4V to 36V - accommodates wide industrial input rails including 12V/24V battery and unregulated SMPS outputs. |
| Feedback Voltage Accuracy | ±2% (1.217V–1.243V at TJ = +25°C) - ensures stable regulation across line/load/temperature for adjustable designs. |
| Shutdown Current | 50 µA typical - minimizes system standby power in battery-powered applications. |
| Thermal Protection | Internal thermal shutdown with 100% electrical burn-in - prevents latch-up or damage during sustained overload. |
| Current Limit Threshold | 4.2A–7.9A peak - provides robust fault handling while allowing brief inrush without false triggering. |
Pinout & Package
MIC4576WU is housed in a 5-lead TO-263 (DDPAK) package with exposed thermal pad (Tab = GND), optimized for high-power dissipation in industrial environments. Thermal resistance θJC = 2°C/W enables efficient heat transfer to PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Unregulated input supply | Accepts 4V–36V; requires local 470 µF/63V bulk capacitor to suppress ripple and sustain transient load demands. |
| SW (Pin 2) | Switch node output | Drives external inductor; connects to cathode of Schottky diode (e.g., MBR360); high dv/dt node requiring tight layout. |
| GND / Tab (Pins 3 & Tab) | Power and signal ground | Common return path for input/output currents; thermal pad must be soldered to ≥2 cm² copper pour for thermal performance. |
| FB (Pin 4) | Feedback input | Connects to 1.23V tap of external resistor divider (R1/R2); bias current ≤100 nA enables high-impedance dividers. |
| SHDN (Pin 5) | Enable/disable control | TTL-compatible input; <1.2V enables regulator, >2.4V disables it; draws ≤30 µA when active. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 200 kHz operation | Enables predictable EMI filtering and consistent inductor sizing-no external frequency programming required. |
| Adjustable 1.23V–33V output | Supports custom voltage rails (e.g., 12V, 15V, 24V) using only two precision resistors-no part variants needed. |
| Integrated thermal & overcurrent protection | Eliminates need for external fault monitoring circuitry-reduces BOM count and board area. |
| Standard inductor compatibility | Works with off-the-shelf 33 µH or 68 µH inductors (e.g., Coiltronics PL52C-33-1000), avoiding custom magnetics. |
| Internal frequency compensation | Removes requirement for external compensation network-simplifies design validation and reduces layout sensitivity. |
Applications
| Industrial Power Supply | Battery Charger |
|---|---|
Use Scenario: Converting 24V rail to 12V/3A for PLC I/O modules in factory automation cabinets. IC Role / Device Role / Timing Role: Primary step-down regulator providing stable, high-current DC output with thermal resilience in enclosed enclosures. Use Value: 75%+ efficiency at full load reduces heat buildup; TO-263 package allows direct mounting to heatsink-equipped PCBs. | Use Scenario: Charging 3S Li-ion packs (12.6V nominal) from 16V–36V solar or vehicle sources. IC Role / Device Role / Timing Role: Constant-voltage stage regulator with precise feedback tolerance ensuring cell-balancing readiness. Use Value: ±2% VFB accuracy maintains charge voltage within ±0.25V-critical for battery longevity and safety compliance. |
| On-Card Switching Regulator | Negative Boost Converter |
Use Scenario: Local 5V/3A supply on embedded computing carrier board powered by 12V backplane. IC Role / Device Role / Timing Role: Compact, self-contained buck converter replacing linear regulators to avoid thermal derating. Use Value: TO-263 footprint (10.16 × 8.89 mm) fits dense layouts; minimal external components reduce assembly cost. | Use Scenario: Generating –12V from +12V input for op-amp biasing in instrumentation front-ends. IC Role / Device Role / Timing Role: Inverting buck-boost topology controller using same external components as standard buck. Use Value: 200 kHz frequency allows smaller magnetics than 52 kHz alternatives-cutting board space by ~40%. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC4576WT | Same IC die, but in TO-220 package with higher θJA (65°C/W) and no thermal pad; identical electrical specs. | Suitable for lower-power or forced-air-cooled designs where PCB copper area is limited. | Select MIC4576WT if mechanical mounting favors through-hole or heatsink clip attachment instead of surface-mount thermal pads. |
| LM2576HVS-ADJ | 52 kHz switching frequency, larger inductor requirements, ±3% feedback tolerance, wider input range (4–60V). | Better suited for ultra-low-noise or high-input-voltage applications where EMI filtering dominates layout constraints. | Choose LM2576HVS-ADJ only when input exceeds 36V or when legacy 52 kHz design reuse is mandatory. |
Compared with MIC4576WT, MIC4576WU offers superior thermal performance via TO-263 thermal pad; compared with LM2576HVS-ADJ, it delivers higher efficiency and smaller passive components at the cost of reduced max input voltage.
Availability
MIC4576WU is available at Aetrix Electronics and suitable for industrial power supplies, battery charging systems, and embedded computing platforms requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for MIC4576WU 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and power management ICs, with global manufacturing and quality certifications including ISO 9001 and AEC-Q200.
The MIC4576 family was designed as a drop-in upgrade to LM2576 for industrial and automotive auxiliary power supplies-emphasizing higher efficiency, smaller magnetics, and enhanced thermal reliability in surface-mount form factors.
FAQ
What is the maximum input voltage rating for MIC4576WU?
The absolute maximum input voltage for MIC4576WU is +40V, but the recommended operating maximum is +36V per datasheet specifications. Exceeding +36V risks violating operating ratings and may trigger thermal shutdown or reduce long-term reliability-even though the device survives brief transients up to +40V. Always design with margin: use input clamping or pre-regulation if system rails exceed 36V. MIC4576WU's internal protection does not guarantee safe operation beyond its specified +36V limit.
Does MIC4576WU require an external compensation network?
No, MIC4576WU includes fully internal frequency compensation-no external capacitors or resistors are needed on the FB pin or elsewhere. This simplifies layout, eliminates tuning iterations, and improves stability across temperature and load variations. The internal compensation is optimized for standard 33 µH inductors and 1000 µF output capacitors used in reference designs. MIC4576WU's fixed compensation ensures consistent loop response without user intervention.
Can MIC4576WU be used in negative-output (inverting) configurations?
Yes, MIC4576WU supports inverting buck-boost topology to generate negative output voltages-for example, –12V from +12V input-as documented in Microchip's application notes and Figure 4-6. The IC's SW pin functions as the switching node in both buck and inverting modes; only external component polarity and grounding change. MIC4576WU's 200 kHz frequency and 3A switch capability make it well-suited for compact negative rail generation where size and efficiency matter.
What is the thermal resistance (θJC) of MIC4576WU, and how should it guide heatsinking?
MIC4576WU has a junction-to-case thermal resistance (θJC) of 2°C/W, measured from die to the exposed thermal tab. This low value means >90% of heat flows through the tab into PCB copper-not ambient air-so effective heatsinking requires a minimum 2 cm² solid copper pour connected directly to the tab with multiple thermal vias. Relying solely on θJA (65°C/W) will underestimate temperature rise. MIC4576WU's thermal performance is maximized only when the tab is properly soldered and thermally coupled.
How does the SHDN pin interface with microcontroller GPIOs?
The SHDN pin of MIC4576WU is TTL-compatible: it turns the regulator ON when pulled below 1.2V (typical VSDTH_ON) and OFF when above 2.4V (VIH). A standard 3.3V or 5V MCU GPIO can drive it directly-no level shifter needed. Input current is ≤30 µA, so even weak GPIOs (e.g., STM32 low-drive modes) can control MIC4576WU reliably. MIC4576WU remains disabled until SHDN falls below threshold, preventing brown-out glitches during power-up sequencing.
MIC4576WU 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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 33V
- 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
MIC4576WU FAQ
1.How can I place an order for MIC4576WU through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4576WU 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 MIC4576WU reliable?
The price and inventory of MIC4576WU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4576WU is usually 5 days.
3.What payment methods are accepted for MIC4576WU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4576WU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4576WU?
MIC4576WU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4576WU 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 MIC4576WU?
For technical support, including MIC4576WU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4576WU requirements.
6.How does Aetrix verify that MIC4576WU is sourced from the original manufacturer or authorized distributors?
All MIC4576WU 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 MIC4576WU meets industry standards.
7.What is the process for return or replacement of MIC4576WU?
All MIC4576WU units undergo pre-shipment inspection (PSI). If there is an issue with MIC4576WU, 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 MIC4576WU part is unused and in its original packaging.
Return procedure for MIC4576WU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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