My Inquiry
My Account
Microchip Technology MIC4576-3.3WU
- Part No.:
- MIC4576-3.3WU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC4576-3.3WU.pdf
- Description:
- IC REG BUCK 3.3V 3A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:135
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MIC4576-3.3WU from Microchip Technology is a fixed-output 3.3V, 3A step-down (buck) switching regulator in a 5-lead TO-263 (DDPAK) package, operating at 200 kHz with ±3% output voltage accuracy over 6V–36V input and full load range, designed for high-efficiency power conversion in space-constrained industrial applications.
For engineers reviewing the MIC4576-3.3WU datasheet, MIC4576-3.3WU pinout, MIC4576-3.3WU application, or MIC4576-3.3WU equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternatives, and supply-chain support tailored to OEM and embedded power design workflows.
Technical Context
The MIC4576-3.3WU integrates a BiCMOS 3A NPN switch, 1.23V bandgap reference, and 200 kHz oscillator with cycle-by-cycle current limiting and thermal shutdown. Its fixed 3.3V output eliminates external feedback resistors, simplifying layout while maintaining ±3% regulation across –40°C to +85°C.
It uses internal frequency compensation and requires only three external components (inductor, input/output capacitors, Schottky diode) to deliver up to 3A continuous output. The TO-263 package provides low θJC = 2°C/W thermal resistance for reliable operation under sustained 3A loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±3% (3.168V–3.432V) across 6V–36V input and 0.5A–3A load - ensures stable core logic rail for microprocessors without trimming. |
| Switch Current | Guaranteed 3A peak switch current - supports continuous 3A DC output with margin for transient surges. |
| Input Voltage Range | 4V to 36V - enables direct use with 12V/24V industrial rails, automotive batteries, and wide-input off-line pre-regulation. |
| Switching Frequency | 200 kHz ±10% - allows ~2× smaller inductors than LM2576 (52 kHz), reducing board area and cost without EMI penalty. |
| Efficiency | 72% typical at 3A load - minimizes thermal dissipation in compact enclosures; improves system-level power density vs. linear regulators. |
| Shutdown Current | <200 µA typical - enables low-power standby modes in battery-backed or energy-sensitive systems. |
| Thermal Protection | Integrated thermal shutdown with 100% electrical burn-in - prevents latch-up or damage during overload or poor heatsinking. |
Pinout & Package
Package: 5-lead TO-263 (DDPAK), surface-mount, with exposed thermal pad (Tab = GND). θJA = 65°C/W, θJC = 2°C/W - requires PCB copper pour under Tab for thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Unregulated input supply | Accepts 4V–36V; must be decoupled with ≥470 µF low-ESR capacitor close to pin to suppress ripple and sustain peak current. |
| SW (Pin 2) | Switch node output | Drives external inductor; connects to cathode of Schottky diode; high dv/dt node requiring tight loop layout to minimize EMI. |
| GND / Tab (Pins 3 & Tab) | Power and signal ground | Common return for input cap, output cap, diode, and IC substrate; Tab must be soldered to large PCB copper area for thermal conduction. |
| FB (Pin 4) | Feedback input | Internally tied to 3.3V divider; short directly to output for fixed version - no external resistors needed. |
| SHDN (Pin 5) | Enable/disable control | TTL-compatible; ≤0.8V enables regulator, ≥2.4V disables it; draws <30 µA when active, <200 µA in shutdown. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3V output | Eliminates external feedback resistors - reduces BOM count, layout complexity, and calibration risk in production. |
| 200 kHz switching | Enables use of standard 33 µH inductors (25% value of LM2576 equivalents) - cuts filter size/cost while retaining low-frequency EMI profile. |
| 3A guaranteed switch current | Supports full 3A continuous output without derating at +85°C ambient - simplifies thermal design for industrial 24V-to-3.3V conversion. |
| Internal compensation | Removes need for external compensation network - accelerates design cycle and avoids stability tuning errors. |
| Thermal shutdown + OCP | Self-protecting under short-circuit or overheating - enables robust field operation without external fault management circuitry. |
Applications
| Intel Pentium™ Core Rail Supply | Industrial 24V-to-3.3V Pre-regulator |
|---|---|
Use Scenario: Powering 3.3V I/O and core logic of legacy Intel Pentium-class microprocessors in embedded controllers. IC Role / Device Role / Timing Role: Primary step-down regulator delivering clean, regulated 3.3V at up to 3A with fast transient response. Use Value: Meets ±3% output tolerance requirement for Pentium I/O rails; 200 kHz operation reduces inductor footprint versus 52 kHz alternatives. | Use Scenario: Converting unregulated 24V factory bus to stable 3.3V for PLC I/O modules, sensors, and communication interfaces. IC Role / Device Role / Timing Role: High-current buck converter providing efficient, thermally robust local regulation in harsh industrial environments. Use Value: 4V–36V input range accommodates brownout and surge conditions; TO-263 package enables direct heatsink mounting on metal enclosures. |
| Battery-Powered Test Equipment | Ruggedized Edge Node Power |
Use Scenario: Supplying 3.3V to MCU, ADC, and wireless transceivers in portable handheld test instruments powered by Li-ion or lead-acid packs. IC Role / Device Role / Timing Role: Main DC/DC converter enabling long runtime via high efficiency and ultra-low shutdown current. Use Value: 72% efficiency at 3A extends battery life; <200 µA shutdown current preserves charge during extended idle periods. | Use Scenario: Providing primary 3.3V rail in outdoor edge computing nodes exposed to –40°C to +85°C ambient and vibration. IC Role / Device Role / Timing Role: Industrial-grade buck regulator with guaranteed operation across full temperature range and built-in fault protection. Use Value: –40°C to +85°C rating and thermal shutdown ensure reliability in uncontrolled environments; TO-263 mechanical robustness resists shock-induced solder fatigue. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC4576-3.3WT | Same IC die, but in TO-220 package - higher θJA (65°C/W same), but through-hole mounting and easier heatsinking. | Preferred for prototyping, low-volume assemblies, or where manual rework is required; less suitable for automated SMT lines. | Select MIC4576-3.3WT if board assembly uses through-hole process or requires simplified thermal testing with clip-on heatsinks. |
| LM2576-3.3 | 52 kHz operation, larger inductor requirement, ±4% output tolerance, same 3A rating - older architecture with lower integration. | Used where legacy designs mandate pin compatibility or where EMI filtering favors lower frequency; lacks SHDN pin logic level spec. | Select LM2576-3.3 only for drop-in replacement in existing LM2576-based boards; MIC4576-3.3WU offers superior efficiency, smaller magnetics, and tighter regulation. |
Compared with MIC4576-3.3WT, the MIC4576-3.3WU enables higher-density SMT layouts and better thermal coupling to PCB copper; compared with LM2576-3.3, it delivers 2× smaller inductors, 1% tighter output tolerance, and integrated shutdown control - making it optimal for new industrial and embedded designs.
Availability
MIC4576-3.3WU is available at Aetrix Electronics and suitable for industrial automation, embedded computing, and battery-powered instrumentation requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle continuity.
Supply support for MIC4576-3.3WU 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 industrial, automotive, and IoT applications.
The MIC4576 product line delivers easy-to-use, high-current buck regulators targeting cost-sensitive, space-constrained power designs where simplicity, reliability, and thermal performance are critical - especially in industrial control and legacy processor power.
FAQ
What is the maximum input voltage rating for the MIC4576-3.3WU?
The MIC4576-3.3WU has an absolute maximum input voltage (VIN) rating of +40V, with recommended continuous operation up to +36V. Exceeding +36V may trigger overvoltage stress or reduce reliability. The device is specified for stable 3.3V output across 6V–36V input, making it ideal for 12V/24V industrial rails. Always include input transient suppression if used in automotive or inductive-load environments.
Does the MIC4576-3.3WU require external feedback resistors?
No, the MIC4576-3.3WU does not require external feedback resistors. As a fixed-output variant, it integrates an internal resistive divider referenced to the 1.23V bandgap, connecting the FB pin internally to the 3.3V output node. The FB pin must be shorted directly to the output capacitor's positive terminal - no resistor network is needed, reducing BOM count and layout sensitivity.
What is the thermal resistance (θJC) of the MIC4576-3.3WU package?
The MIC4576-3.3WU in its 5-lead TO-263 (DDPAK) package has a junction-to-case thermal resistance (θJC) of 2°C/W. This low value reflects efficient heat transfer from the silicon die to the exposed thermal tab, which must be soldered to a large PCB copper area for effective thermal management. Combined with θJA = 65°C/W, proper tab grounding enables full 3A operation at +85°C ambient.
Can the MIC4576-3.3WU be used in negative-output (inverting) configurations?
Yes, the MIC4576-3.3WU can be configured as a positive-to-negative inverting buck-boost converter per Microchip Application Note AN14. In this topology, the SW pin drives an inductor to ground, and the output is taken from the junction of inductor and diode referenced to VIN. While the fixed 3.3V version is optimized for step-down, its internal switch and control architecture support inverting operation - though output voltage magnitude and regulation accuracy differ from standard buck mode.
What is the shutdown threshold voltage for the MIC4576-3.3WU SHDN pin?
The MIC4576-3.3WU SHDN pin has a turn-on threshold (VSDTH_ON) of 1.2V (typical) and a turn-off threshold (VSDTH_OFF) of 1.4V (typical), with TTL-compatible logic levels: VIH ≥ 2.4V for disable, VIL ≤ 0.8V for enable. This hysteresis prevents chatter near the transition point. When disabled, shutdown current is typically 50 µA - critical for low-power sleep modes in battery applications using MIC4576-3.3WU.
MIC4576-3.3WU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- 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
MIC4576-3.3WU FAQ
1.How can I place an order for MIC4576-3.3WU through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4576-3.3WU 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 MIC4576-3.3WU reliable?
The price and inventory of MIC4576-3.3WU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4576-3.3WU is usually 5 days.
3.What payment methods are accepted for MIC4576-3.3WU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4576-3.3WU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4576-3.3WU?
MIC4576-3.3WU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4576-3.3WU 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 MIC4576-3.3WU?
For technical support, including MIC4576-3.3WU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4576-3.3WU requirements.
6.How does Aetrix verify that MIC4576-3.3WU is sourced from the original manufacturer or authorized distributors?
All MIC4576-3.3WU 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 MIC4576-3.3WU meets industry standards.
7.What is the process for return or replacement of MIC4576-3.3WU?
All MIC4576-3.3WU units undergo pre-shipment inspection (PSI). If there is an issue with MIC4576-3.3WU, 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 MIC4576-3.3WU part is unused and in its original packaging.
Return procedure for MIC4576-3.3WU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MIC4576-3.3WU Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
