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Microchip Technology MIC4576WT
- Part No.:
- MIC4576WT
- Manufacturer:
- Microchip Technology
- Package:
- TO-220-5
- Datasheet:
-
MIC4576WT.pdf
- Description:
- IC REG BUCK ADJ 3A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,366
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Product details
Overview
MIC4576WT from Microchip Technology is an adjustable-output, 200 kHz, 3A step-down (buck) switching regulator in a 5-lead TO-220 package. It operates from 4V to 36V input, delivers 1.23V–33V output with ±2% feedback voltage tolerance, and integrates thermal shutdown and cycle-by-cycle current limiting. It serves as a high-efficiency preregulator for microprocessor power rails or industrial DC-DC conversion.
For engineers reviewing the MIC4576WT datasheet, MIC4576WT pinout, MIC4576WT application, or MIC4576WT equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternatives, and supply-chain support details specific to the adjustable TO-220 variant.
Technical Context
The MIC4576WT implements a fixed-frequency (200 kHz ±10%) BiCMOS buck topology with internal 3A NPN switch, 1.23V bandgap reference, and error amplifier driving a PWM comparator. Its oscillator frequency enables up to 2:1 reduction in inductor size versus LM2576-based designs.
It features TTL-compatible shutdown control (1.2V turn-on / 1.4V turn-off thresholds), internal frequency compensation, and guaranteed operation across –40°C to +85°C. The device draws <200 µA in shutdown and supports adjustable output via external resistor divider on FB pin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 200 kHz ±10% - Enables smaller output filter inductors (e.g., 68 µH for 12V out) vs. 52 kHz competitors. |
| Output Current | Guaranteed 3A continuous - Supports high-current loads like microprocessor core rails without derating at 25°C. |
| Input Voltage Range | 4V to 36V - Accepts wide-range unregulated inputs including 12V/24V industrial buses and automotive battery transients. |
| Output Voltage Range | 1.23V to 33V adjustable - Set via external R1/R2 divider; 1.23V reference allows precise low-voltage regulation (e.g., 1.8V, 3.3V, 5V, 12V). |
| Feedback Voltage Tolerance | ±2% (1.217V–1.243V) - Ensures stable output regulation under line/load variations without external trimming. |
| Shutdown Current | 50 µA typical - Minimizes system standby power; compatible with battery-backed or always-on applications. |
| Thermal Protection | Internal thermal shutdown - Activates at +150°C junction temperature; recovers automatically after cooldown. |
Pinout & Package
Package: 5-Lead TO-220 (T), with tab connected to GND. Thermal resistance θJA = 65°C/W, θJC = 2°C/W - requires heatsink for >1.5A continuous operation at elevated ambient temperatures.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: VIN | Unregulated input supply | Accepts 4–36V DC; must be bypassed with ≥470 µF/63V electrolytic capacitor near pin for stability. |
| 2: SW | Switch node output | Drives external inductor (e.g., 68 µH); connects to cathode of Schottky diode (e.g., MBR360) in standard buck layout. |
| 3 & Tab: GND | Power and signal ground | Common return for input cap, output cap, feedback divider, and heatsink; low-impedance path critical for EMI control. |
| 4: FB | Feedback input | Connects to 1.23V tap of R1/R2 divider; 50 nA bias current enables high-resistance dividers (e.g., 1.5kΩ/13kΩ for 12V). |
| 5: SHDN | Enable/shutdown control | TTL-compatible logic input; <1.2V enables regulator, >2.4V disables it; 4 µA max input current simplifies MCU GPIO interfacing. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 200 kHz switching frequency | Enables predictable EMI filtering and consistent inductor sizing; eliminates need for external frequency programming components. |
| Integrated 3A NPN power switch | Eliminates external MOSFET and driver; reduces BOM count and PCB area while maintaining full 3A load capability. |
| ±2% feedback voltage tolerance | Ensures output accuracy without trimming; supports tight-tolerance applications like FPGA I/O rails or analog subsystems. |
| Standard inductor compatibility | Uses common off-the-shelf inductors (e.g., Coiltronics PL52C-68-1000); no custom magnetics required for most designs. |
| Thermal shutdown + overcurrent protection | Self-protecting under short-circuit or overload; no external sensing circuitry needed for robust field deployment. |
Applications
| Industrial Power Supply | Microprocessor Preregulator |
|---|---|
|
Use Scenario: Converting 24V factory bus to 12V intermediate rail for PLC I/O modules. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated 12V/3A with ripple <150 mVpp. Use Value: Replaces LM2576-based designs with 40% smaller inductor (68 µH vs. 120 µH) and higher efficiency (77% at 3A). |
Use Scenario: Generating 3.3V for Intel Pentium™-class CPU core logic from 12V motherboard rail. IC Role / Device Role / Timing Role: High-current preregulator feeding low-dropout linear regulator (LDO) for ultra-low-noise core supply. Use Value: Delivers clean, stable 3.3V at 3A with ±3% output tolerance; enables LDO to operate with minimal dropout margin. |
| Battery Charger Interface | Negative Boost Converter |
|
Use Scenario: Charging 12V sealed lead-acid battery from variable solar panel output (16–36V). IC Role / Device Role / Timing Role: Constant-voltage buck stage regulating charge voltage to 13.8V with current limiting disabled externally. Use Value: Adjustable output allows precise charge voltage setting; thermal shutdown prevents damage during float-stage overtemperature. |
Use Scenario: Generating –5V from +12V supply for op-amp biasing in instrumentation front-ends. IC Role / Device Role / Timing Role: Inverting buck-boost converter using MIC4576WT in non-inverting buck configuration with polarity-reversed output. Use Value: Leverages same external component set as positive buck; achieves –5V/1.5A with <100 mVpp ripple using standard 33 µH inductor. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC4576WU | Same IC die, but in 5-lead TO-263 (DDPAK) package; θJA = 65°C/W, θJC = 2°C/W - identical thermal performance but surface-mount compatible. | Preferred for automated SMT assembly; requires different PCB footprint and reflow profile vs. through-hole TO-220. | Select MIC4576WU when board space is constrained and SMT manufacturing is used; no electrical redesign needed. |
| LM2576HVS-ADJ | 52 kHz switching frequency; 3A rating; wider input range (4–60V); ±2% feedback tolerance; requires larger inductor (≈2× size) and has lower efficiency (≈68% at 3A). | Used where legacy LM2576 footprint compatibility is mandatory; not suitable for noise-sensitive or space-constrained designs. | Choose LM2576HVS-ADJ only for drop-in replacement in existing LM2576 layouts; MIC4576WT offers superior size/performance tradeoff for new designs. |
Compared with MIC4576WU, the MIC4576WT offers identical electrical performance but requires through-hole assembly and heatsink mounting; compared with LM2576HVS-ADJ, it delivers 9% higher efficiency and 40% smaller magnetics at the cost of reduced max input voltage (36V vs. 60V).
Availability
MIC4576WT is available at Aetrix Electronics and suitable for industrial power supplies, microprocessor preregulators, battery charger interfaces, and negative boost converters requiring stable component supply and long-term production continuity.
Supply support for MIC4576WT 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 semiconductor company specializing in microcontrollers, analog devices, and power management ICs, with a focus on reliability and long-life product support.
The MIC4576 series was designed as a pin-compatible upgrade to the LM2576 for industrial and embedded applications demanding higher efficiency, smaller magnetics, and extended temperature operation (–40°C to +85°C).
FAQ
What is the maximum input voltage for the MIC4576WT?
The MIC4576WT has an absolute maximum input voltage rating of +40V, but its specified operating input range is +4V to +36V. Exceeding 36V may cause premature failure or violate safety margins defined in the datasheet. For reliable operation, keep VIN ≤ 36V under all conditions including transients.
How do I set the output voltage for the MIC4576WT?
The MIC4576WT is an adjustable regulator requiring an external resistive divider between VOUT and GND, with the FB pin connected to the midpoint. Use R1 = 1.50 kΩ and R2 = 13.0 kΩ to achieve 12V output (VOUT = 1.23V × (1 + R2/R1)). The feedback voltage is tightly regulated to 1.23V ±2%, ensuring accurate output setting.
Does the MIC4576WT require an external compensation network?
No, the MIC4576WT includes internal frequency compensation. No external capacitors or resistors are needed on the FB pin or elsewhere to stabilize the control loop. This simplifies design and reduces component count compared to controllers requiring external compensation.
Can the MIC4576WT be used in a negative output configuration?
Yes - the MIC4576WT can be configured as an inverting buck-boost converter to generate negative outputs. In this mode, the GND pin becomes the negative output rail, VIN supplies the positive input, and the SW pin drives the inductor to ground. Refer to Figure 4-5 in DS20006158A for implementation guidance.
What thermal management is required for the MIC4576WT at 3A load?
At 3A continuous load and 25°C ambient, the MIC4576WT dissipates ≈2.5W (based on 77% efficiency at 12V→12V). With θJA = 65°C/W, junction temperature rises ≈163°C above ambient - exceeding the +85°C limit. A heatsink reducing θJA to ≤25°C/W is required; the TO-220 tab must be electrically connected to GND and thermally coupled to the heatsink.
MIC4576WT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-220-5
- 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:
- Through Hole
- Supplier Device Package:
- TO-220-5
MIC4576WT FAQ
1.How can I place an order for MIC4576WT through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4576WT 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 MIC4576WT reliable?
The price and inventory of MIC4576WT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4576WT is usually 5 days.
3.What payment methods are accepted for MIC4576WT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4576WT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4576WT?
MIC4576WT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4576WT 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 MIC4576WT?
For technical support, including MIC4576WT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4576WT requirements.
6.How does Aetrix verify that MIC4576WT is sourced from the original manufacturer or authorized distributors?
All MIC4576WT 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 MIC4576WT meets industry standards.
7.What is the process for return or replacement of MIC4576WT?
All MIC4576WT units undergo pre-shipment inspection (PSI). If there is an issue with MIC4576WT, 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 MIC4576WT part is unused and in its original packaging.
Return procedure for MIC4576WT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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