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Microchip Technology MIC4575BU
- Part No.:
- MIC4575BU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC4575BU.pdf
- Description:
- IC REG BUCK BST ADJ 1.7A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,927
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Product details
Overview
MIC4575BU from Microchip Technology is a 1A, 200 kHz fixed-frequency step-down (buck) DC-DC regulator in DDPAK-5 package, supporting adjustable output voltage from 1.23V to 20V with ±2% feedback voltage tolerance. It operates across 4V–24V input, delivers up to 1A load current, and integrates thermal shutdown and cycle-by-cycle overcurrent protection. Used in compact on-card power supplies for microprocessors and battery chargers.
For engineers reviewing the MIC4575BU datasheet, MIC4575BU pinout, MIC4575BU application, or MIC4575BU equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options, and supply-chain support details specific to the MIC4575BU variant.
Technical Context
The MIC4575BU implements a BiCMOS buck topology with internal 1A NPN switch, 200 kHz oscillator (±10%), and 1.23V bandgap reference. Its error amplifier compares FB voltage against 1.23V and modulates duty cycle via PWM comparator against a sawtooth waveform.
It features integrated cycle-by-cycle current limiting (1.7–3.0 A peak), thermal shutdown, and <200 µA shutdown quiescent current. Frequency compensation is fully internal, requiring no external capacitor - enabling minimal external component count including standard inductors sized at 25% of typical LM2575 values.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 200 kHz ±10% - enables smaller output filter inductors (up to 2× size reduction vs. 52 kHz LM2575) |
| Output Current | 1 A guaranteed continuous - supports high-current loads like microprocessor core rails or battery charging circuits |
| Input Voltage Range | 4 V to 24 V - compatible with wide-range industrial and automotive inputs without pre-regulation |
| Output Voltage Range | 1.23 V to 20 V (adjustable) - set via external resistor divider; 1.23V reference tolerance ±2% ensures tight regulation |
| Efficiency | 77% typ. at 1A/5V - reduces thermal load and improves power density in space-constrained designs |
| Shutdown Current | <200 µA - enables low-power standby modes in battery-powered or energy-sensitive systems |
| Thermal Protection | Integrated thermal shutdown - prevents damage during overload or poor heatsinking; θJA = 65°C/W (DDPAK) |
Pinout & Package
Package: 5-Lead DDPAK (U), surface-mount, thermally enhanced with exposed tab (Pin 3/TAB = GND). Designed for industrial temperature range (–40°C to +85°C) and RoHS-compliant with high-melting solder exemption.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Unregulated input supply | Accepts 4–24 V DC; must be decoupled with ≥22 µF ceramic or low-ESR electrolytic capacitor |
| 2 (SW) | Switch node output | Drives external inductor and Schottky diode; high dv/dt node requiring careful PCB layout and ground plane |
| 3 / TAB (GND) | Power and signal ground | Exposed thermal pad connects to PCB ground plane for thermal dissipation and noise control |
| 4 (FB) | Feedback input | Connects to 1.23V tap of resistive divider; bias current ≤100 nA minimizes divider error |
| 5 (SHDN) | Enable/shutdown control | TTL-compatible input; logic low (≤0.8 V) enables regulator; logic high (≥2.4 V) disables with <200 µA quiescent draw |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 200 kHz operation | Enables predictable EMI filtering and consistent inductor sizing; eliminates need for external frequency programming |
| Internal frequency compensation | Removes requirement for external compensation network - simplifies design and improves stability across load/line variations |
| Standard inductor compatibility | Works with off-the-shelf inductors rated at only 25% of typical LM2575 values - reduces BOM cost and board area |
| Thermal shutdown + overcurrent protection | Self-protecting under fault conditions; eliminates need for external current-sense or thermal monitoring circuitry |
| Low shutdown current | <200 µA standby draw allows use in always-on systems without compromising battery life or system efficiency |
Applications
| Microprocessor Core Supply | Battery Charging Circuit |
|---|---|
Use Scenario: Generating 3.3V or 5V rail for Intel Pentium-class or similar microprocessors from 6–24V input. IC Role / Device Role / Timing Role: Primary step-down regulator delivering regulated DC power with fast transient response and low output ripple. Use Value: High efficiency (>72%) minimizes heat generation near CPU; 1A capability supports peak current demands during burst execution. |
Use Scenario: Charging Li-ion or lead-acid batteries from variable unregulated sources such as solar panels or vehicle alternators. IC Role / Device Role / Timing Role: Constant-voltage/constant-current pre-regulator stage controlling charge voltage and limiting input current. Use Value: Adjustable output (1.23–20V) enables precise charge voltage setting; thermal shutdown protects against overcharge-induced overheating. |
| On-Card Switching Regulator | Positive-to-Negative Converter |
Use Scenario: Local point-of-load conversion on dense PCBs where linear regulators would overheat or waste power. IC Role / Device Role / Timing Role: Compact, self-contained buck converter replacing inefficient linear regulators in embedded modules. Use Value: DDPAK-5 package offers superior thermal performance vs. TO-220 in constrained spaces; minimal external parts reduce footprint. |
Use Scenario: Generating –5V rail from +8–18V input using inverting buck-boost topology. IC Role / Device Role / Timing Role: Core switching controller configured in inverting mode with external inductor and dual Schottky diodes. Use Value: 200 kHz operation allows smaller magnetics than 52 kHz alternatives; internal current limit prevents diode or inductor saturation during startup. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC4575-5.0WU | Fixed 5.0V output; ±3% output tolerance vs. MIC4575BU's ±2% FB tolerance; identical pinout and package | Suitable where fixed 5V is required without external feedback divider; eliminates two resistors but loses adjustability | Select when system requires stable 5V without tuning; not interchangeable with MIC4575BU in adjustable designs |
| LM2575HVS-ADJ | 52 kHz switching frequency; higher minimum input voltage (4.75V); requires external compensation; larger inductor needed | Legacy design reuse where EMI constraints favor lower frequency; less efficient at same output current due to lower fSW | Choose only if backward compatibility with existing LM2575 layouts is mandatory; otherwise MIC4575BU offers superior size/efficiency trade-off |
Compared with MIC4575-5.0WU, the MIC4575BU provides design flexibility through output adjustability and tighter feedback accuracy; compared with LM2575HVS-ADJ, it delivers higher efficiency, smaller magnetics, and simplified layout - making it optimal for new compact, high-performance buck designs.
Availability
MIC4575BU is available at Aetrix Electronics and suitable for microprocessor core supplies, battery charging circuits, on-card switching regulators, and positive-to-negative converters requiring stable component supply, long-term lifecycle assurance, and industrial-grade thermal reliability.
Supply support for MIC4575BU 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 robust, easy-to-use solutions for industrial, automotive, and consumer applications.
The MIC4575BU belongs to Microchip's MIC4575 series of BiCMOS buck regulators, designed specifically to replace legacy LM2575-based designs with higher frequency, improved efficiency, and reduced external component count.
FAQ
What is the maximum input voltage rating for the MIC4575BU?
The MIC4575BU has an absolute maximum input voltage rating of +40V, but its recommended operating input voltage range is +4V to +24V. Operation above +24V is not guaranteed and may cause permanent damage, especially under short-circuit conditions. The MIC4575BU datasheet explicitly states that survival under short-circuit is not assured for inputs exceeding 24V.
Does the MIC4575BU require external compensation components?
No, the MIC4575BU does not require external compensation components. Its frequency compensation is fully internal, allowing stable operation with only the essential external parts: input/output capacitors, inductor, and feedback resistors (for adjustable versions). This eliminates tuning complexity and improves reliability across temperature and load variations.
What is the thermal resistance (θJA) of the MIC4575BU in its DDPAK package?
The MIC4575BU in the 5-Lead DDPAK (U) package has a junction-to-ambient thermal resistance (θJA) of 65°C/W under standard JEDEC test conditions. Its junction-to-case (θJC) is 2°C/W, confirming the exposed thermal tab must be soldered to a large copper ground plane for effective heat dissipation in 1A continuous operation.
Can the MIC4575BU be used in a negative-output (inverting) configuration?
Yes, the MIC4575BU can be configured as a positive-to-negative inverting buck-boost converter. The datasheet includes Figure 4-8 showing a split ±5V supply using MIC4575BU with external transformer and dual Schottky diodes. Its 200 kHz switching frequency and internal current limiting make it suitable for this topology while maintaining stability and protection.
What is the shutdown input logic threshold for the MIC4575BU?
The MIC4575BU SHDN pin is TTL-compatible: a logic low ≤0.8 V (at VOUT = 3.3V or 5V) enables regulation, while a logic high ≥2.4 V disables it. In shutdown, quiescent current drops to <200 µA. Input current is ≤30 µA when SHDN = 5V (off) and ≤10 µA when SHDN = 0V (on), ensuring minimal loading on control logic.
MIC4575BU 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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 24V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 20V
- 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
MIC4575BU FAQ
1.How can I place an order for MIC4575BU through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4575BU 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 MIC4575BU reliable?
The price and inventory of MIC4575BU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4575BU is usually 5 days.
3.What payment methods are accepted for MIC4575BU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4575BU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4575BU?
MIC4575BU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4575BU 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 MIC4575BU?
For technical support, including MIC4575BU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4575BU requirements.
6.How does Aetrix verify that MIC4575BU is sourced from the original manufacturer or authorized distributors?
All MIC4575BU 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 MIC4575BU meets industry standards.
7.What is the process for return or replacement of MIC4575BU?
All MIC4575BU units undergo pre-shipment inspection (PSI). If there is an issue with MIC4575BU, 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 MIC4575BU part is unused and in its original packaging.
Return procedure for MIC4575BU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MIC4575BU Tags
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