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Microchip Technology MIC4576BU
- Part No.:
- MIC4576BU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC4576BU.pdf
- Description:
- IC REG BUCK ADJ 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,538
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Product details
Overview
MIC4576BU from Microchip Technology is a 200 kHz fixed-frequency, 3A step-down (buck) switching regulator in TO-263 (DDPAK) package, supporting adjustable output voltage from 1.23V to 33V. It operates across 4V–36V input, delivers ±2% feedback voltage accuracy, integrates thermal shutdown and cycle-by-cycle current limiting, and is used in industrial power supplies requiring compact, high-current DC/DC conversion.
For engineers reviewing the MIC4576BU datasheet, MIC4576BU pinout, MIC4576BU application, or MIC4576BU equivalent, key selection criteria include guaranteed 3A switch current, 200 kHz fixed oscillator frequency, internal compensation, shutdown current <200 µA, and compatibility with standard inductors at reduced size versus LM2576.
Technical Context
The MIC4576BU implements a BiCMOS synchronous-buck architecture with an integrated 3A NPN power switch, 1.23V bandgap reference, and error amplifier driving a 200 kHz sawtooth comparator for duty-cycle control. Its fixed-frequency PWM operation enables predictable EMI filtering and stable loop response without external compensation components.
Thermal protection activates at +150°C junction temperature, and overcurrent protection uses cycle-by-cycle peak-current limiting with 4.2–7.9A trip threshold. The SHDN pin provides TTL-compatible logic-level enable/disable with 1.2V turn-on and 1.4V turn-off thresholds, drawing only 50 µA in shutdown mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Current | Guaranteed 3A continuous output current - supports high-power loads without external current boosting. |
| Oscillator Frequency | 200 kHz ±10% - enables smaller output filter inductors (≈50% size reduction vs. 52 kHz LM2576) and predictable EMI profile. |
| Input Voltage Range | 4V to 36V - accommodates wide industrial input rails including 12V, 24V, and 32V battery or bus systems. |
| Output Voltage Range | 1.23V to 33V (adjustable) - configured via external resistor divider; 1.23V reference enables precise low-voltage regulation. |
| Feedback Accuracy | ±2% over line/load/temp - ensures stable output under varying conditions without trimming. |
| Shutdown Current | <200 µA typical - minimizes standby power loss in battery-powered or energy-sensitive applications. |
| Thermal Resistance | θJC = 2°C/W - enables efficient heat transfer from die to case, supporting high ambient operation with minimal heatsink. |
Pinout & Package
The MIC4576BU is housed in a 5-lead TO-263 (DDPAK) surface-mount package with exposed thermal pad (Tab = GND), optimized for high-current thermal performance and PCB layout simplicity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Unregulated input supply | Accepts 4V–36V; requires local ceramic bypass capacitor near pin for high-frequency stability. |
| SW (Pin 2) | Switch node output | Drives external inductor; high di/dt node requiring short, low-inductance PCB trace to minimize ringing. |
| GND / Tab (Pins 3 & Tab) | Power and signal ground | Exposed thermal pad must be soldered to large copper pour for thermal conduction and low-impedance return path. |
| FB (Pin 4) | Feedback input | Connects to 1.23V tap of resistive divider; high-impedance node sensitive to noise - route away from SW. |
| SHDN (Pin 5) | Enable/disable control | TTL-compatible logic input; pull low to enable, >2.4V to disable; internal 4–30 µA bias current. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 200 kHz switching frequency | Enables consistent EMI filtering design and eliminates need for external frequency programming components. |
| Internal frequency compensation | Reduces BOM count by eliminating external compensation network - simplifies layout and validation. |
| Standard inductor compatibility | Supports off-the-shelf inductors with values ≈25% of those required for LM2576 - lowers cost and footprint. |
| Thermal shutdown + overcurrent protection | Self-protecting under fault conditions; no external circuitry needed for safe operation in unattended systems. |
| Low shutdown current (<200 µA) | Extends battery life in portable equipment and enables always-on monitoring circuits with minimal quiescent drain. |
Applications
| Industrial Power Supply | Embedded System Preregulator |
|---|---|
Use Scenario: Converting 24V rail to 5V/3A for PLC I/O modules operating in harsh factory environments. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated, regulated 5V supply with high efficiency and thermal resilience. Use Value: Delivers 77% efficiency at 3A load and survives 85°C ambient via θJC = 2°C/W, reducing need for forced air cooling. | Use Scenario: Generating 3.3V intermediate rail from 12V for microcontroller, memory, and peripheral ICs on a dense embedded board. IC Role / Device Role / Timing Role: High-current preregulator stepping down voltage before LDO post-regulation to reduce thermal stress on linear stages. Use Value: Reduces power dissipation in downstream LDOs by delivering clean 3.3V at up to 3A with ±2% feedback accuracy. |
| Negative Boost Converter | Battery Charger Control |
Use Scenario: Implementing inverting buck-boost topology to generate –12V from 12V input for op-amp biasing in test instrumentation. IC Role / Device Role / Timing Role: Core switching controller reconfigured as negative-output converter using standard external components. Use Value: Leverages same 200 kHz timing and 3A switch capability - avoids redesign when polarity inversion is required. | Use Scenario: Charging 3S Li-ion packs (12.6V max) from 15–36V automotive or solar input with constant-current/constant-voltage control. IC Role / Device Role / Timing Role: Adjustable-output buck stage regulating charging voltage; FB pin interfaced with charger IC's sense amplifier. Use Value: Wide 1.23–33V output range allows precise CV setpoint tuning; thermal shutdown prevents cell damage during fault. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576HVS-ADJ | 52 kHz switching frequency; larger inductor requirement; TO-220/TO-263 available; ±2% feedback tolerance. | Lower frequency increases EMI filtering complexity and inductor size; less suitable for space-constrained designs. | Select LM2576HVS-ADJ only if legacy compatibility or lower EMI at fundamental frequency is prioritized over size/efficiency. |
| MIC4576WT | Same die, TO-220 through-hole package; identical electrical specs; higher θJA (65°C/W) but same θJC (2°C/W). | Requires through-hole assembly; better suited for prototyping or high-reliability mechanical mounting. | Choose MIC4576WT for manual assembly, thermal testing fixtures, or where mechanical robustness outweighs PCB area savings. |
Compared with LM2576HVS-ADJ and MIC4576WT, the MIC4576BU offers identical regulation performance in a surface-mount TO-263 package with superior thermal interface (exposed tab), enabling higher power density and automated manufacturing compatibility without sacrificing reliability.
Availability
MIC4576BU is available at Aetrix Electronics and suitable for industrial power supplies, embedded system preregulators, and battery charger designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MIC4576BU 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 for select products.
The MIC4576BU belongs to Microchip's high-current buck regulator product line, designed specifically for industrial and embedded applications demanding rugged, easy-to-use DC/DC conversion with minimal external components and robust fault protection.
FAQ
What is the maximum input voltage rating for the MIC4576BU?
The MIC4576BU has an absolute maximum input voltage rating of +40V, with recommended continuous operation up to +36V. Exceeding +36V may trigger internal protection or cause permanent damage. The device is rated for 4V–36V normal operation, making it suitable for 24V industrial buses and 32V battery systems. Always include input transient suppression if operating near the 36V limit.
Does the MIC4576BU require external compensation components?
No, the MIC4576BU features fully internal frequency compensation - no external capacitors or resistors are needed for loop stability. This simplifies design, reduces BOM count, and eliminates tuning effort. The internal compensation is optimized for standard output capacitor ESR ranges and typical inductor values used with this 200 kHz regulator.
What is the function of the TAB connection on the MIC4576BU package?
The TAB on the MIC4576BU is electrically connected to Pin 3 (GND) and serves as the primary thermal conduction path from the silicon die to the PCB. It must be soldered to a large, thermally robust copper pour for effective heat dissipation. Leaving the TAB unconnected degrades thermal performance and risks thermal shutdown under full 3A load.
Can the MIC4576BU be used in a negative-output (inverting) configuration?
Yes, the MIC4576BU can be configured as a negative-output buck-boost converter per Microchip Application Note AN14. In this topology, the SW pin drives the inductor to ground while the output is taken from the inductor–diode junction referenced to VIN. The feedback network must be adapted accordingly, and layout must preserve ground integrity to avoid instability.
What is the guaranteed minimum switch current for the MIC4576BU across temperature?
The MIC4576BU guarantees 3A switch current across the full industrial temperature range of –40°C to +85°C. This is validated per datasheet Electrical Characteristics tables and supported by thermal design using the specified θJC = 2°C/W and proper PCB copper area. Derating is not required within this range when thermal design guidelines are followed.
MIC4576BU 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:
- 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
MIC4576BU FAQ
1.How can I place an order for MIC4576BU through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4576BU 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 MIC4576BU reliable?
The price and inventory of MIC4576BU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4576BU is usually 5 days.
3.What payment methods are accepted for MIC4576BU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4576BU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4576BU?
MIC4576BU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4576BU 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 MIC4576BU?
For technical support, including MIC4576BU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4576BU requirements.
6.How does Aetrix verify that MIC4576BU is sourced from the original manufacturer or authorized distributors?
All MIC4576BU 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 MIC4576BU meets industry standards.
7.What is the process for return or replacement of MIC4576BU?
All MIC4576BU units undergo pre-shipment inspection (PSI). If there is an issue with MIC4576BU, 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 MIC4576BU part is unused and in its original packaging.
Return procedure for MIC4576BU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MIC4576BU Tags
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