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Microchip Technology MIC4681-2.5BM
- Part No.:
- MIC4681-2.5BM
- Manufacturer:
- Microchip Technology
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MIC4681-2.5BM.pdf
- Description:
- IC REG BUCK 2.5V 1A 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,280
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Product details
Overview
MIC4681-2.5BM from Micrel is a fixed-output 2.5V, 200kHz voltage-mode buck regulator in SOP-8 package, delivering up to 1A continuous output current over 4V–30V input range. It integrates an NPN power switch, internal compensation, and cycle-by-cycle current limiting, optimized for GSM battery charging and compact high-efficiency DC/DC conversion.
For engineers reviewing the MIC4681-2.5BM datasheet, MIC4681-2.5BM pinout, MIC4681-2.5BM application, or MIC4681-2.5BM equivalent, key selection criteria include its 2.5V fixed output, 2.1A minimum current limit, thermal shutdown at 160°C, <6µA shutdown current, and compatibility with standard surface-mount inductors and Schottky diodes in space-constrained designs.
Technical Context
The MIC4681-2.5BM implements voltage-mode control using a 1.23V internal bandgap reference and a 200kHz oscillator. Its error amplifier compares FB voltage against 1.23V to generate duty-cycle-modulated PWM driving an integrated NPN switch.
It features frequency foldback during short-circuit (down to ~60kHz), cycle-by-cycle current limiting with 2.2–4.5A trip threshold, and thermal shutdown at 160°C. The power-SOP-8 package uses pins 5–8 as a unified ground paddle for low θJC (20°C/W) and enhanced thermal dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.5V ±1% (set internally; no external feedback resistors required) |
| Switching Frequency | 200kHz ±10% - enables compact magnetics and predictable EMI profile |
| Continuous Output Current | 1A at TA ≤ 60°C with ≥6 cm² ground plane - defines usable load capacity under thermal constraints |
| Input Voltage Range | 4V to 30V - supports wide industrial and automotive supply rails without pre-regulation |
| Shutdown Current | 6µA typical when VSHDN = VIN - ensures ultra-low system standby power |
| Current Limit Threshold | 2.2A min (short-circuit), 2.1A min (pulsed) - sustains GSM burst-mode charging without latch-off |
| Thermal Shutdown | 160°C junction temperature - provides robust fault protection without external sensors |
Pinout & Package
Package: 8-lead SOP (M), power-enhanced variant with integrated die-attach paddle connected to pins 5–8 (GND). Junction temperature range: –40°C to +125°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SHDN) | Shutdown control input | TTL-compatible logic input; <1.25V enables regulation, >2V disables with 0.8V hysteresis |
| 2 (VIN) | Main power input | Accepts 4V–30V unregulated supply; requires local 22µF/35V ceramic or tantalum bypass |
| 3 (SW) | Switch node output | Drives external inductor and Schottky diode; high dv/dt node requiring tight layout |
| 4 (FB) | Feedback reference point | Internally tied to 1.23V reference; unused in fixed-2.5V version (MIC4681-2.5BM) |
| 5–8 (GND) | Power and signal ground | Common thermal and electrical return; must connect to ≥6 cm² PCB ground plane for 1A operation |
Key Features
| Feature | Design Value |
|---|---|
| Integrated NPN power switch | Eliminates external MOSFET and gate driver; reduces BOM count and layout complexity |
| Internal frequency compensation | Enables stable operation with standard 68µH inductor and 220µF output capacitor-no loop tuning required |
| 2.1A minimum pulsed current limit | Supports GSM TDMA burst profiles (e.g., 2A peak for 500µs) without shutdown or dropout |
| Power-SOP-8 thermal design | Pins 5–8 form unified ground paddle; achieves θJC = 20°C/W for reliable 1A continuous operation |
| Frequency foldback under fault | Reduces switching frequency to ~60kHz during short-circuit, limiting power dissipation and enabling self-recovery |
Applications
| Cellular Phone Battery Charger | GSM Power Supply |
|---|---|
Use Scenario: Charging Li-ion batteries in dual-mode (GSM/TDMA) handsets with pulsed 2A load profiles. IC Role / Device Role / Timing Role: Primary buck regulator providing regulated 2.5V bias to charging IC or directly powering charge pump circuitry. Use Value: 2.1A current limit and fast transient response maintain stable 2.5V output during RF transmit bursts without brownout. | Use Scenario: Generating clean 2.5V rail for baseband processor I/O or RF front-end bias in GSM modules. IC Role / Device Role / Timing Role: Fixed-output step-down converter replacing linear regulators to improve efficiency and reduce thermal load. Use Value: 90% peak efficiency at 1A and <6µA shutdown current extend battery life in sleep/idle modes. |
| Industrial Sensor Node Power | Legacy System Voltage Translation |
Use Scenario: Powering 2.5V ADCs, precision references, or low-power microcontrollers in 12–24V industrial field devices. IC Role / Device Role / Timing Role: Primary DC/DC converter converting wide-input industrial bus to stable 2.5V analog domain supply. Use Value: 4V–30V input range eliminates need for upstream pre-regulator; thermal shutdown protects against enclosure overheating. | Use Scenario: Replacing obsolete TO-220 linear regulators (e.g., LM78L25) in legacy equipment requiring 2.5V at ≤1A. IC Role / Device Role / Timing Role: Drop-in buck replacement delivering same output voltage with >75% less heat generation. Use Value: SOP-8 footprint and identical 2.5V output simplify redesign; 1A capability exceeds most LM78L25 applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC2605-2.5YM | Same manufacturer, lead-free SOP-8, identical 2.5V fixed output and 1A rating, but rated for –40°C to +125°C with improved ESD tolerance | Preferred for new designs requiring RoHS compliance and extended ESD robustness (4kV HBM) | Select MIC2605-2.5YM when lead-free assembly and higher ESD immunity are mandatory; pinout and layout are identical. |
| TPS54202DR | TI part; 2.5V adjustable via external resistors, 4.5–28V input, 2A capability, but requires external compensation and has different shutdown polarity (active-high) | Suitable where higher output current or programmable UVLO is needed, but increases design complexity | Choose TPS54202DR only if >1A output or adjustable features justify added components and layout changes. |
Compared with MIC4681-2.5BM, MIC2605-2.5YM offers direct drop-in replacement with enhanced manufacturability, while TPS54202DR trades simplicity for flexibility and higher current-neither is pin-compatible, but both serve overlapping 2.5V buck use cases with distinct trade-offs in integration and qualification scope.
Availability
MIC4681-2.5BM is available at Aetrix Electronics and suitable for cellular phone battery chargers, industrial sensor nodes, and legacy system voltage translation requiring stable component supply across extended temperature and long production lifecycles.
Supply support for MIC4681-2.5BM 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, analog, and interface ICs before its acquisition by Microchip Technology in 2015.
The MIC4681-2.5BM belongs to Micrel's SuperSwitcher™ family of integrated buck regulators, designed specifically for high-efficiency, low-component-count DC/DC conversion in space- and thermally-constrained portable and industrial applications.
FAQ
What is the output voltage tolerance of the MIC4681-2.5BM?
The MIC4681-2.5BM delivers a fixed 2.5V output with ±1% tolerance over temperature and line/load conditions, as confirmed by its internal 1.23V reference and trimmed feedback network. This tight tolerance ensures reliable operation for precision analog circuits and low-voltage logic without external calibration. The MIC4681-2.5BM maintains this accuracy across its full –40°C to +125°C junction temperature range and 4V–30V input span.
Does the MIC4681-2.5BM require external feedback resistors?
No, the MIC4681-2.5BM does not require external feedback resistors because it is a factory-trimmed fixed-output variant. Its FB pin is internally connected to generate precisely 2.5V, eliminating resistor selection, placement, and tolerance errors. This simplifies design and improves long-term stability compared to adjustable versions like MIC4681BM. The MIC4681-2.5BM's fixed architecture also removes potential noise coupling paths associated with external resistor networks.
What is the maximum continuous output current for the MIC4681-2.5BM at 60°C ambient?
The MIC4681-2.5BM supports up to 1A continuous output current at 60°C ambient temperature when mounted on a PCB with ≥6 cm² ground plane area connected to pins 5–8. This rating assumes 12V input and 2.5V output, with efficiency near 85%. Exceeding 1A requires derating based on thermal resistance (θJA ≈ 63°C/W) and ambient conditions. The MIC4681-2.5BM's thermal shutdown at 160°C prevents damage during temporary overloads.
Can the MIC4681-2.5BM be used in GSM pulse-charging applications?
Yes, the MIC4681-2.5BM is explicitly qualified for GSM pulse-charging applications due to its 2.1A minimum current limit and fast transient response. It sustains 2A pulsed output within typical GSM charging environments without dropout or thermal shutdown. The MIC4681-2.5BM's cycle-by-cycle current limiting and frequency foldback protect against sustained shorts during burst-mode operation, making it suitable for battery charger IC bias rails in dual-mode handsets.
What package type and thermal characteristics define the MIC4681-2.5BM?
The MIC4681-2.5BM uses Micrel's power-SOP-8 (M) package, where pins 5–8 form a unified ground paddle bonded directly to the die for low thermal resistance. Its junction-to-case (θJC) is 20°C/W, and typical junction-to-ambient (θJA) is 63°C/W with proper PCB grounding. This thermal design enables 1A continuous operation without a heatsink. The MIC4681-2.5BM operates from –40°C to +125°C junction temperature, with thermal shutdown activating at 160°C.
MIC4681-2.5BM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- SuperSwitcher™
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 1A
- Frequency - Switching:
- 200kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MIC4681-2.5BM FAQ
1.How can I place an order for MIC4681-2.5BM through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4681-2.5BM 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 MIC4681-2.5BM reliable?
The price and inventory of MIC4681-2.5BM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4681-2.5BM is usually 5 days.
3.What payment methods are accepted for MIC4681-2.5BM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4681-2.5BM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4681-2.5BM?
MIC4681-2.5BM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4681-2.5BM 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 MIC4681-2.5BM?
For technical support, including MIC4681-2.5BM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4681-2.5BM requirements.
6.How does Aetrix verify that MIC4681-2.5BM is sourced from the original manufacturer or authorized distributors?
All MIC4681-2.5BM 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 MIC4681-2.5BM meets industry standards.
7.What is the process for return or replacement of MIC4681-2.5BM?
All MIC4681-2.5BM units undergo pre-shipment inspection (PSI). If there is an issue with MIC4681-2.5BM, 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 MIC4681-2.5BM part is unused and in its original packaging.
Return procedure for MIC4681-2.5BM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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