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Microchip Technology MIC4576BT
- Part No.:
- MIC4576BT
- Manufacturer:
- Microchip Technology
- Package:
- TO-220-5
- Datasheet:
-
MIC4576BT.pdf
- Description:
- IC REG BUCK ADJ 3A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,464
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Product details
Overview
MIC4576BT from Microchip Technology is a 200 kHz fixed-frequency, 3A step-down (buck) switching regulator in TO-220 package, delivering ±3% output voltage accuracy at 5.0V under 0.5–3A load and 8–36V input. It integrates a 3A NPN switch, internal 1.23V bandgap reference, and cycle-by-cycle current limiting-designed for high-efficiency preregulation in industrial power supplies and microprocessor core rails.
For engineers reviewing the MIC4576BT datasheet, MIC4576BT pinout, MIC4576BT application, or MIC4576BT equivalent, this page delivers verified electrical specs, thermal behavior, shutdown logic thresholds, feedback tolerance, and real-world buck converter design constraints-including inductor sizing reduction versus LM2576 and thermal resistance (θJC = 2°C/W).
Technical Context
The MIC4576BT implements a BiCMOS-based voltage-mode PWM controller with a fixed 200 kHz oscillator (±10% tolerance), 1.23V internal bandgap reference, and error amplifier driving a comparator against a sawtooth waveform. Its NPN output switch features 1.7–2.3V saturation voltage at 3A, enabling efficient operation across 4–36V input range.
Thermal protection includes junction-limited shutdown at +150°C and built-in 100% electrical burn-in. The device supports TTL-compatible shutdown control (VSDTH_ON = 1.2V, VSDTH_OFF = 1.4V), draws <200 µA in shutdown, and maintains ±3% output regulation over line/load variations within its industrial temperature range (–40°C to +85°C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 200 kHz ±10% - enables ~2× smaller output inductors vs. 52 kHz LM2576; reduces filter size without compromising stability. |
| Output Voltage | Fixed 5.0V ±3% - guaranteed across 8–36V input and 0.5–3A load; meets Intel Pentium™ core rail requirements. |
| Max Switch Current | 3A continuous - supports full-load operation with 4.2–7.9A peak current limit; avoids external current-sense components. |
| Input Voltage Range | 4V to 36V - accommodates wide industrial DC inputs including 12V/24V bus systems and battery-backed supplies. |
| Efficiency | 77% typical at 3A - achieved with low RDS(on)-equivalent saturation (1.7–2.3V) and minimal quiescent current (5–10 mA). |
| Shutdown Current | 50 µA typical - enables ultra-low-power standby mode; compatible with microcontroller-controlled power sequencing. |
| Junction Temp Range | –40°C to +85°C - rated for industrial environments; θJC = 2°C/W ensures effective heatsink coupling in TO-220 package. |
Pinout & Package
Package: 5-Lead TO-220 (T), tab-connected to GND; thermally enhanced metal tab enables direct heatsink mounting with θJC = 2°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Unregulated Input Supply | Accepts 4–36V DC; must be decoupled with ≥470 µF low-ESR capacitor to sustain 3A pulsed current. |
| 2 - SW | Switch Node Output | Emitter of internal NPN transistor; connects directly to inductor and Schottky diode anode; handles high dv/dt switching. |
| 3 & Tab - GND | Power Ground / Thermal Pad | Common return for input/output paths and thermal interface; tab must be soldered to PCB copper pour for thermal management. |
| 4 - FB | Feedback Input | Monitors regulated 5.0V output via internal resistor divider; open-circuit or short-circuit triggers regulation loss or shutdown. |
| 5 - SHDN | Shutdown Control Input | TTL-compatible enable: ≤0.8V enables regulator; ≥2.4V disables it; draws <30 µA when active, <200 µA in shutdown. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 5.0V Output | Guaranteed ±3% accuracy across full line/load/temperature range-eliminates external feedback resistors and calibration. |
| 200 kHz Switching | Reduces required inductor value by ~2× vs. legacy 52 kHz regulators-enables compact 33 µH designs instead of 68 µH. |
| Integrated Protection | Cycle-by-cycle current limiting + thermal shutdown + 100% electrical burn-in-ensures robust fault recovery without external circuitry. |
| Low Shutdown Current | 50 µA typical-supports battery-powered systems requiring multi-day standby without significant drain. |
| TO-220 Thermal Performance | θJC = 2°C/W-allows direct heatsink attachment to tab for >3A continuous operation at ambient up to +70°C. |
Applications
| Industrial Power Supply Preregulator | Microprocessor Core Rail (5V) |
|---|---|
Use Scenario: Converts 24V industrial bus to stable 5V for downstream linear regulators or point-of-load converters. IC Role / Device Role / Timing Role: Primary buck regulator providing high-efficiency, low-noise 5V intermediate rail with tight line/load regulation. Use Value: Reduces heat generation versus linear solutions; enables compact 33 µH inductor and eliminates need for external current sensing. |
Use Scenario: Supplies 5V/3A to Intel Pentium™ and similar microprocessors requiring precise core voltage with fast transient response. IC Role / Device Role / Timing Role: Fixed-output step-down regulator delivering regulated 5.0V with ±3% accuracy and 200 kHz ripple frequency. Use Value: Meets processor spec for voltage tolerance; integrated thermal shutdown prevents damage during sustained load conditions. |
| Battery Charger Front-End | Negative Boost Converter |
Use Scenario: Steps down variable 12–36V automotive or lead-acid battery input to constant 5V for charging circuitry. IC Role / Device Role / Timing Role: High-input-voltage buck regulator operating across wide battery SOC range without dropout. Use Value: Maintains regulation down to 4V VIN; shutdown pin enables charger enable/disable synchronized with battery state. |
Use Scenario: Configured as inverting buck-boost to generate –5V from positive 12V supply for analog sensor biasing or op-amp rails. IC Role / Device Role / Timing Role: Switch-mode topology reusing same 5V fixed-output IC in non-standard inverting configuration. Use Value: Leverages existing 5V BOM part for dual-rail generation; requires only polarity reversal of inductor/diode placement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576-5.0 | 52 kHz switching, ±4% output tolerance, higher inductor values required, no integrated thermal shutdown burn-in. | Lower EMI but larger magnetics; less suitable for space-constrained 3A designs needing high efficiency. | Select MIC4576BT where board area, thermal performance, or tighter output accuracy are critical. |
| MIC24045-5.0WT | 4 MHz synchronous buck, 5V ±1%, 4A rating, integrated MOSFETs, requires external compensation. | Higher efficiency (>90%) and smaller footprint, but demands more complex layout and higher component count. | Choose MIC4576BT for drop-in replacement simplicity, proven reliability in industrial environments, and minimal external parts. |
Compared with LM2576-5.0 and MIC24045-5.0WT, the MIC4576BT offers superior thermal robustness (2°C/W θJC), simpler design (no compensation needed), and tighter 5V accuracy-making it optimal for cost-sensitive, thermally demanding 3A buck applications where layout simplicity matters.
Availability
MIC4576BT is available at Aetrix Electronics and suitable for industrial power supplies, microprocessor core rails, and battery charger front-ends requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MIC4576BT 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 emphasis on industrial, automotive, and aerospace reliability standards.
The MIC4576BT belongs to Microchip's legacy BiCMOS buck regulator family, designed specifically for high-current, fixed-output DC-DC conversion in cost-sensitive industrial systems where ease of use and thermal resilience are prioritized.
FAQ
What is the maximum input voltage rating for the MIC4576BT?
The MIC4576BT has an absolute maximum input voltage rating of +40V, but its recommended operating input voltage range is +4V to +36V. Exceeding +36V may trigger internal protection or reduce reliability. The MIC4576BT is commonly used with 12V, 24V, or 36V industrial supplies, and its 36V upper limit supports wide-range battery and adapter inputs without derating.
Does the MIC4576BT require external compensation components?
No, the MIC4576BT includes internal frequency compensation and requires no external capacitors or resistors for loop stability. This simplifies design and reduces BOM count-only input/output capacitors, an inductor, and a Schottky diode are needed. The MIC4576BT achieves stable regulation across its full 0.5–3A load range using standard 33 µH inductors and 470–1000 µF electrolytic capacitors.
How does the MIC4576BT handle thermal overload conditions?
The MIC4576BT incorporates thermal shutdown that activates at +150°C junction temperature, halting switching until die temperature falls below the hysteresis threshold. It also undergoes 100% electrical thermal limit burn-in during manufacturing. When mounted on a heatsink via its TO-220 tab (θJC = 2°C/W), the MIC4576BT sustains 3A continuous output at ambient temperatures up to +70°C without throttling.
Can the MIC4576BT be used in negative-output configurations?
Yes-the MIC4576BT can be configured as an inverting buck-boost converter to generate negative voltages such as –5V from a positive input. This requires reversing the inductor and diode orientation relative to the standard buck layout, while retaining the same MIC4576BT pin connections. The MIC4576BT's robust 3A switch and fixed 5V feedback path remain fully functional in this topology.
What is the shutdown pin logic level compatibility for the MIC4576BT?
The MIC4576BT SHDN pin is TTL-compatible: logic low (≤0.8V) enables regulation, and logic high (≥2.4V) disables it. Turn-on and turn-off thresholds are specified at 1.2V and 1.4V respectively, providing noise margin. The MIC4576BT draws only 50 µA in shutdown mode, making it suitable for microcontroller-driven power sequencing in battery-operated equipment.
MIC4576BT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-220-5
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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
MIC4576BT FAQ
1.How can I place an order for MIC4576BT through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4576BT 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 MIC4576BT reliable?
The price and inventory of MIC4576BT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4576BT is usually 5 days.
3.What payment methods are accepted for MIC4576BT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4576BT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4576BT?
MIC4576BT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4576BT 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 MIC4576BT?
For technical support, including MIC4576BT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4576BT requirements.
6.How does Aetrix verify that MIC4576BT is sourced from the original manufacturer or authorized distributors?
All MIC4576BT 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 MIC4576BT meets industry standards.
7.What is the process for return or replacement of MIC4576BT?
All MIC4576BT units undergo pre-shipment inspection (PSI). If there is an issue with MIC4576BT, 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 MIC4576BT part is unused and in its original packaging.
Return procedure for MIC4576BT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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