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Microchip Technology MIC4575-3.3BU
- Part No.:
- MIC4575-3.3BU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC4575-3.3BU.pdf
- Description:
- IC REG BCK BST 3.3V 1.7A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,606
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Product details
Overview
MIC4575-3.3BU from Microchip Technology is a fixed-output 3.3V, 1A synchronous step-down (buck) DC-DC regulator with 200 kHz switching frequency, ±3% output voltage tolerance over 6–24V input and 0.2–1A load, thermal shutdown, and cycle-by-cycle current limiting-designed for Intel Pentium-compatible microprocessor power rails.
For engineers reviewing the MIC4575-3.3BU datasheet, MIC4575-3.3BU pinout, MIC4575-3.3BU application, or MIC4575-3.3BU equivalent, this page delivers verified electrical specs, package mapping, functional context, and real-world use cases for high-efficiency buck conversion in industrial and embedded systems.
Technical Context
The MIC4575-3.3BU integrates a BiCMOS NPN power switch, internal 1.23V bandgap reference, error amplifier, and 200 kHz oscillator to deliver fixed 3.3V regulation via direct FB-to-VOUT connection. It operates across 4–24V input while maintaining ±3% output accuracy under full line/load conditions.
Its architecture enables cycle-by-cycle current limiting (1.7–3.0 A peak), thermal shutdown, and <200 µA shutdown quiescent current. The device uses external inductor-diode-capacitor filtering and requires no external compensation due to internal frequency compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 3.3 V ±3% (guaranteed across 6–24V input, 0.2–1A load) |
| Switching Frequency | 200 kHz ±10% (enables ~2× smaller inductors vs. 52 kHz LM2575) |
| Max Switch Current | 1 A continuous (with thermal shutdown at TJ > +150°C) |
| Input Voltage Range | 4 V to 24 V (absolute max +40 V; short-circuit survival limited to ≤24 V) |
| Efficiency | 72% typical at 1 A load (reduces heat dissipation vs. linear regulators) |
| Shutdown Current | <200 µA (TTL-compatible SHDN pin pulls regulator into ultra-low-power state) |
| Thermal Resistance | θJC = 2°C/W (DDPAK package enables high-power density PCB layout) |
Pinout & Package
The MIC4575-3.3BU is housed in a 5-lead DDPAK (TO-263) surface-mount package with exposed thermal pad (TAB connected to GND). This thermally enhanced package supports high-current operation without heatsink in moderate airflow environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Unregulated Input Supply | Accepts 4–24 V DC; must be decoupled with ≥22 µF low-ESR capacitor near pin |
| 2 (SW) | Switch Node Output | Drives external inductor; connects to cathode of Schottky diode and inductor top |
| 3 & TAB (GND) | Power and Signal Ground | Common return for internal regulator, feedback, and thermal path; TAB must be soldered to large copper pour |
| 4 (FB) | Feedback Input | Internally tied to 3.3V divider; connect directly to regulated output for closed-loop control |
| 5 (SHDN) | Enable/Shutdown Control | TTL-compatible input: logic low (≤0.8 V) enables regulator; logic high (≥2.4 V) disables with <200 µA draw |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3V Output | Eliminates external resistor divider-reduces BOM count and layout sensitivity vs. adjustable versions |
| 200 kHz Switching | Enables use of standard 68 µH inductors (25% size of typical LM2575 designs), reducing board area and cost |
| Integrated Protection | Combines cycle-by-cycle current limiting, thermal shutdown, and internal soft-start to prevent inrush damage |
| Low Shutdown IQ | <200 µA standby current extends battery life in always-on systems requiring periodic wake-up |
| Wide Input Range | Supports 4–24 V operation-suitable for 5 V, 12 V, and 24 V industrial bus rails without pre-regulation |
Applications
| Intel Pentium Core Power | Battery-Powered Embedded Systems |
|---|---|
Use Scenario: Providing stable 3.3V core supply to legacy Intel Pentium-class microprocessors in industrial controllers. IC Role / Device Role / Timing Role: Primary step-down regulator delivering 1A continuous current with tight ±3% output tolerance. Use Value: Replaces LM2575-based designs with higher efficiency (72% vs. ~65%) and reduced filter component size. |
Use Scenario: Powering ARM Cortex-M4-based sensor nodes operating from 2-cell Li-ion (6–8.4 V) or 9 V alkaline batteries. IC Role / Device Role / Timing Role: Main buck converter enabling long runtime via 72% efficiency and <200 µA shutdown current. Use Value: Extends battery life by minimizing quiescent loss during sleep mode while supporting full-load bursts. |
| Industrial PLC I/O Modules | POS Terminal Power Rails |
Use Scenario: Generating isolated 3.3V logic supply from 24 V DC field bus in programmable logic controller backplanes. IC Role / Device Role / Timing Role: Non-isolated buck regulator with thermal shutdown protecting against ambient temperature excursions up to +85°C. Use Value: Delivers robust 1A output with built-in overcurrent and thermal protection-no external sensing required. |
Use Scenario: Powering display, keypad, and communication interfaces in point-of-sale terminals using 12 V wall adapters. IC Role / Device Role / Timing Role: Compact, surface-mount buck regulator replacing TO-220 solutions to reduce assembly height and cost. Use Value: DDPAK package enables automated SMT placement and improves thermal performance on dense PCBs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575-3.3 | 52 kHz switching, TO-220 only, ±4% output tolerance, lower efficiency (~65%), larger inductor requirement | Legacy designs requiring drop-in replacement with identical pinout but accepting lower performance | Select when redesign is not feasible and 52 kHz ripple is acceptable |
| MIC24045-3.3WU | 2.2 MHz switching, integrated MOSFETs, 3A output, ±1% output tolerance, requires external compensation | High-density applications needing smaller magnetics, faster transient response, and higher current headroom | Select when upgrading for size reduction, efficiency gain, or future-proofing beyond 1A loads |
Compared with LM2575-3.3, MIC4575-3.3BU offers 200 kHz operation and tighter regulation; compared with MIC24045-3.3WU, it provides simpler design with no external compensation but lower switching frequency and current capability.
Availability
MIC4575-3.3BU is available at Aetrix Electronics and suitable for industrial PLCs, embedded microprocessor power supplies, battery-powered instrumentation, and point-of-sale terminals requiring stable component supply and long-term manufacturability.
Supply support for MIC4575-3.3BU 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 a focus on reliability, longevity, and industrial-grade qualification.
The MIC4575 series was developed as a high-frequency, drop-in upgrade to the LM2575 family-targeting cost-sensitive, space-constrained industrial and embedded applications requiring simple, robust buck conversion.
FAQ
What is the maximum input voltage rating for the MIC4575-3.3BU?
The MIC4575-3.3BU has an absolute maximum input voltage of +40 V, but its operational input range is specified from +4 V to +24 V. Microchip explicitly notes that the device is not guaranteed to survive a short-circuit to ground for input voltages above 24 V-so system-level overvoltage protection should clamp transients before reaching the VIN pin of the MIC4575-3.3BU.
Does the MIC4575-3.3BU require external compensation components?
No, the MIC4575-3.3BU does not require external compensation components. Its control loop is internally compensated, allowing stable operation with only the standard external inductor, output capacitor, and Schottky diode. This simplifies design and reduces BOM count compared to current-mode controllers requiring RC networks on the COMP or FB pins.
Can the MIC4575-3.3BU be used in negative-output (inverting) configurations?
Yes-the MIC4575-3.3BU can be configured as a positive-to-negative inverting buck-boost converter, as documented in Microchip's DS20006464A (Figure 4-8). In this topology, the GND pin becomes the negative output rail, and the SW pin drives the inductor to generate –3.3 V. Layout must maintain clean return paths and account for reversed polarity on input/output capacitors.
What is the thermal resistance (θJC) of the MIC4575-3.3BU DDPAK package?
The MIC4575-3.3BU in the 5-lead DDPAK (U) package has a junction-to-case thermal resistance (θJC) of 2°C/W, measured from the die to the exposed thermal tab. This low value enables efficient heat transfer to the PCB copper pour, supporting 1A continuous operation without a heatsink under typical industrial ambient conditions (TA ≤ +70°C).
How does the MIC4575-3.3BU handle overcurrent conditions?
The MIC4575-3.3BU implements cycle-by-cycle current limiting with a peak switch current threshold of 1.7–3.0 A. During overload, it reduces duty cycle to hold average output current near 1A while maintaining regulation. If sustained overcurrent causes junction temperature to exceed +150°C, thermal shutdown activates-latching off the switch until cooldown occurs.
MIC4575-3.3BU 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, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck, Buck-Boost
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 24V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.7A (Switch)
- 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
MIC4575-3.3BU FAQ
1.How can I place an order for MIC4575-3.3BU through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4575-3.3BU 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 MIC4575-3.3BU reliable?
The price and inventory of MIC4575-3.3BU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4575-3.3BU is usually 5 days.
3.What payment methods are accepted for MIC4575-3.3BU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4575-3.3BU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4575-3.3BU?
MIC4575-3.3BU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4575-3.3BU 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 MIC4575-3.3BU?
For technical support, including MIC4575-3.3BU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4575-3.3BU requirements.
6.How does Aetrix verify that MIC4575-3.3BU is sourced from the original manufacturer or authorized distributors?
All MIC4575-3.3BU 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 MIC4575-3.3BU meets industry standards.
7.What is the process for return or replacement of MIC4575-3.3BU?
All MIC4575-3.3BU units undergo pre-shipment inspection (PSI). If there is an issue with MIC4575-3.3BU, 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 MIC4575-3.3BU part is unused and in its original packaging.
Return procedure for MIC4575-3.3BU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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