My Inquiry
My Account
Microchip Technology MIC4680-3.3BM
- Part No.:
- MIC4680-3.3BM
- Manufacturer:
- Microchip Technology
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MIC4680-3.3BM.pdf
- Description:
- IC REG BUCK 3.3V 1.3A 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,753
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MIC4680-3.3BM from Micrel is a fixed-output 3.3V, 1.3A continuous current buck regulator in an 8-pin Power SOIC package, operating at 200kHz with 4V–34V input range and internal compensation. It integrates an NPN switch, thermal shutdown, cycle-by-cycle current limiting, and delivers up to 90% efficiency in high-efficiency step-down power conversion for industrial and embedded systems.
For engineers reviewing the MIC4680-3.3BM datasheet, MIC4680-3.3BM pinout, MIC4680-3.3BM application, or MIC4680-3.3BM equivalent, key selection considerations include its fixed 3.3V output accuracy (±1%), shutdown current (<2µA), saturation voltage (1.4V typ at 1A), thermal shutdown threshold (160°C), and compatibility with standard 68µH inductors and Schottky diodes in minimal-component designs.
Technical Context
The MIC4680-3.3BM implements voltage-mode control using a 1.23V internal bandgap reference and a 200kHz oscillator, comparing FB voltage against the reference via a fixed-gain error amplifier to generate variable-duty-cycle PWM. Its internal NPN switch drives external inductor-diode energy transfer, with cycle-by-cycle current limiting triggered when FB = 0V.
Thermal protection activates at 160°C junction temperature, and frequency foldback (30–100kHz) reduces energy per cycle during hard short-circuit conditions. The device uses a Power SOIC-8 package where pins 5–8 and the die-attach paddle form a unified thermal path to PCB ground plane, achieving θJA = 63°C/W with proper layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±1% (guaranteed over 6V–34V input, 0.1A–1A load, –40°C to +125°C) |
| Max Output Current | 1.3A continuous (limited by thermal design; requires ≥6 cm² ground plane for full rating at 125°C ambient) |
| Input Voltage Range | 4V to 34V DC (VIN(min) = VOUT + 2.5V or 4V, whichever is greater) |
| Switching Frequency | 200kHz ±10% (fixed, internally generated; stable across temperature and input voltage) |
| Shutdown Current | 30µA typical at VSHDN = 5V (enables ultra-low-power standby in battery-backed systems) |
| Saturation Voltage | 1.4V typical at IOUT = 1A (directly impacts conduction loss and efficiency at high load) |
| Efficiency | Up to 90% at 1A (measured at 12V input → 3.3V/1A; varies with VIN, load, and component selection) |
| Thermal Shutdown | 160°C junction temperature (self-protecting; auto-recovery after cooldown) |
Pinout & Package
Package: 8-pin Power SOIC (M), with integrated thermal paddle connected to pins 5–8 (GND). Designed for high-power dissipation: θJA = 63°C/W with ≥6 cm² copper ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SHDN) | Shutdown control input | TTL-compatible logic input; <1.0V enables regulation, >1.6V disables (30µA max shutdown current) |
| 2 (IN) | Main power input | Accepts 4V–34V unregulated supply; connects to input capacitor (15µF/35V typical) |
| 3 (SW) | Switch node output | Emitter of internal NPN transistor; connects directly to inductor (68µH) and Schottky diode (B260A/SS26) |
| 4 (FB) | Feedback input | Internally tied to 3.3V output divider; no external resistors required for fixed-output operation |
| 5–8 (GND) | Power and thermal ground | All four pins bonded to die paddle; must connect to large PCB ground plane for thermal management |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated control loop | Eliminates external compensation components; ensures stability with 68µH/220µF output filter (≥35° phase margin) |
| Fixed 200kHz switching | Predictable EMI profile and inductor sizing; avoids audible noise and simplifies filtering |
| Cycle-by-cycle overcurrent protection | Current limit triggers at 1.3A min (FB = 0V); prevents damage during overload or short-circuit |
| Low shutdown quiescent current | 30µA typical at 5V SHDN (supports >1-year battery life in always-on monitoring nodes) |
| Power SOIC-8 thermal architecture | Pins 5–8 + paddle form low-thermal-resistance path to PCB; enables 1.3A continuous without heatsink |
| Wide input voltage range | Supports direct connection to 12V/24V industrial rails, automotive batteries (with transient protection), and telecom supplies |
Applications
| Industrial 12V-to-3.3V Point-of-Load | Embedded System Pre-regulator |
|---|---|
Use Scenario: Converting 12V rail to clean 3.3V for microcontrollers, FPGAs, and sensors in factory automation controllers. IC Role / Device Role / Timing Role: Primary buck regulator providing regulated 3.3V with fast transient response and cycle-by-cycle fault protection. Use Value: Delivers 1.3A at 90% efficiency with only 4 external components, reducing board area vs. TO-220 solutions. | Use Scenario: Stepping down 24V field bus voltage to 5V intermediate rail before final LDO stage in IoT gateway devices. IC Role / Device Role / Timing Role: High-efficiency pre-regulator enabling lower heat generation than linear regulators in multi-rail systems. Use Value: Achieves 85%+ efficiency at 1A while maintaining <2µA shutdown current for deep-sleep modes. |
| Battery-Powered Instrumentation Supply | Positive-to-Negative Inverting Converter |
Use Scenario: Powering portable test equipment from 7.4V Li-ion packs requiring stable 3.3V for ADCs and wireless modules. IC Role / Device Role / Timing Role: Main DC/DC converter with enable control synchronized to measurement cycles. Use Value: Enables >10-hour runtime via 90% peak efficiency and 30µA shutdown current during idle periods. | Use Scenario: Generating –3.3V rail from +3.3V source for op-amp biasing in precision analog front-ends. IC Role / Device Role / Timing Role: Inverting buck-boost configured regulator using same external components as buck mode. Use Value: Eliminates need for separate negative charge pump IC; leverages existing MIC4680-3.3BM inventory and layout. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2678-3.3 | 5A rated, 260kHz fixed frequency, requires external compensation; higher IQ (50mA active) | Better suited for higher-current (>2A) loads; less efficient at light load due to higher quiescent current | Select when output current exceeds 1.3A or when wider input range (8V–40V) is required |
| TPS54331 | 3A rated, 570kHz adjustable frequency, integrated MOSFETs, requires external compensation | Higher switching frequency enables smaller magnetics; lacks built-in thermal shutdown hysteresis | Select when board space is constrained and 3A capability is needed; verify thermal performance under sustained load |
Compared with LM2678-3.3 and TPS54331, the MIC4680-3.3BM offers superior ease-of-use via internal compensation and ultra-low shutdown current, making it optimal for cost-sensitive, thermally constrained 1A designs where minimal BOM count and proven stability are priorities.
Availability
MIC4680-3.3BM is available at Aetrix Electronics and suitable for industrial motor controls, embedded computing power supplies, and battery-powered instrumentation requiring stable component supply, long-lifecycle support, and consistent parametric performance across temperature.
Supply support for MIC4680-3.3BM 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
Micrel Inc. was a U.S.-based semiconductor company specializing in power management, timing, and interface ICs before its acquisition by Microchip Technology in 2015.
The MIC4680 family was designed as a plug-and-play buck regulator solution targeting cost-sensitive, high-reliability industrial and embedded applications where minimal external components and robust thermal protection were critical.
FAQ
What is the guaranteed output voltage tolerance for MIC4680-3.3BM across temperature and load?
The MIC4680-3.3BM guarantees ±1% output voltage tolerance over –40°C to +125°C junction temperature, 6V–34V input, and 0.1A–1A load. At room temperature and nominal input, typical deviation is ±0.3%. This tight tolerance eliminates need for post-regulation trimming in most 3.3V logic applications.
Can MIC4680-3.3BM operate with input voltage below 4V?
No - the MIC4680-3.3BM has a minimum input voltage of 4V per absolute ratings and operating specifications. Attempting operation below 4V may result in dropout, unstable regulation, or failure to start. For sub-4V inputs, consider low-dropout alternatives like the MIC29302 or discrete buck-boost solutions.
How does the shutdown function behave on MIC4680-3.3BM, and what is the logic polarity?
The MIC4680-3.3BM uses active-low shutdown: applying <1.0V to SHDN (Pin 1) enables regulation; >1.6V disables it. Input leakage is ±10µA. When disabled, quiescent current drops to 30µA typical (VSHDN = 5V), making it suitable for battery backup circuits requiring microamp-level standby.
Is external compensation required for stable operation of MIC4680-3.3BM?
No - the MIC4680-3.3BM features fully internal frequency compensation optimized for stability with standard 68µH inductors and 220µF output capacitors. Bode plots confirm >35° phase margin across all operating conditions; adding external compensation risks instability and is not recommended.
What thermal derating applies to MIC4680-3.3BM at elevated ambient temperatures?
At 65°C ambient with 12V input and 1A load, junction temperature reaches ~106°C (calculated using θJA = 63°C/W and 1.33W dissipation). Full 1.3A output is only sustainable up to ~50°C ambient unless PCB ground plane exceeds 6 cm². Derate linearly above that point using the Safe Operating Area chart in the datasheet.
MIC4680-3.3BM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- SuperSwitcher™
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 34V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.3A
- Frequency - Switching:
- 200kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MIC4680-3.3BM FAQ
1.How can I place an order for MIC4680-3.3BM through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4680-3.3BM 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 MIC4680-3.3BM reliable?
The price and inventory of MIC4680-3.3BM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4680-3.3BM is usually 5 days.
3.What payment methods are accepted for MIC4680-3.3BM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4680-3.3BM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4680-3.3BM?
MIC4680-3.3BM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4680-3.3BM 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 MIC4680-3.3BM?
For technical support, including MIC4680-3.3BM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4680-3.3BM requirements.
6.How does Aetrix verify that MIC4680-3.3BM is sourced from the original manufacturer or authorized distributors?
All MIC4680-3.3BM 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 MIC4680-3.3BM meets industry standards.
7.What is the process for return or replacement of MIC4680-3.3BM?
All MIC4680-3.3BM units undergo pre-shipment inspection (PSI). If there is an issue with MIC4680-3.3BM, 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 MIC4680-3.3BM part is unused and in its original packaging.
Return procedure for MIC4680-3.3BM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MIC4680-3.3BM 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
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…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
