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Microchip Technology MIC4681-5.0BM
- Part No.:
- MIC4681-5.0BM
- Manufacturer:
- Microchip Technology
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MIC4681-5.0BM.pdf
- Description:
- IC REG BUCK 5V 1A 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,785
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Product details
Overview
MIC4681-5.0BM from Micrel is a fixed-output 5.0V, 200kHz voltage-mode buck regulator in an 8-lead SOP package, delivering up to 1A continuous output current over a 4V–30V input range. It integrates an NPN power switch, internal compensation, thermal shutdown, and cycle-by-cycle current limiting, and sustains 4.2V/2A pulsed output for GSM battery charging applications.
For engineers reviewing the MIC4681-5.0BM datasheet, MIC4681-5.0BM pinout, MIC4681-5.0BM application, or MIC4681-5.0BM equivalent, key selection considerations include its fixed 5.0V output, 2.1A minimum current limit, <6µA shutdown current, 90% peak efficiency, and thermal design requirements for the Power-SOP-8 package with pins 5–8 as shared ground/power-dissipation terminals.
Technical Context
The MIC4681-5.0BM implements voltage-mode PWM control using a 1.23V internal bandgap reference and a 200kHz oscillator. Its error amplifier compares FB voltage against 1.23V, then modulates duty cycle via comparison with a sawtooth waveform - enabling stable regulation across line, load, and transient conditions.
Protection includes cycle-by-cycle current limiting (2.2–4.5A short-circuit limit), thermal shutdown at ~160°C, and TTL-compatible SHDN input with hysteresis (ON threshold ≤1.25V, OFF threshold ≥2V). The device operates with only four external components and requires no external frequency compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±2%, verified across –40°C to +125°C junction temperature. |
| Switching Frequency | 200kHz ±10%, internally fixed - enables predictable EMI filtering and inductor sizing. |
| Input Voltage Range | 4V to 30V DC - supports wide industrial and automotive battery inputs without pre-regulation. |
| Continuous Output Current | 1A at TA = 25°C with adequate PCB ground plane; derates to ~0.7A at TA = 60°C per SOA curves. |
| Shutdown Current | 6µA typical when VSHDN = VIN, 35µA when VSHDN = 5V - enables ultra-low-power system sleep modes. |
| Current Limit Threshold | 2.2A minimum short-circuit current limit - ensures robust pulsed-current capability for GSM charger bursts. |
| Efficiency | Up to 90% at 12VIN/5VOUT/1A - reduces thermal load and extends battery runtime in portable systems. |
Pinout & Package
The MIC4681-5.0BM uses Micrel's Power-SOP-8 (SOP-8M) package, featuring an exposed die-attach paddle connected to pins 5–8 for enhanced thermal conduction to PCB ground planes. Package dimensions conform to JEDEC MS-012AA, with θJA = 63°C/W (typical) and θJC = 20°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SHDN) | Shutdown control input | TTL-compatible enable: logic low (≤0.8V) activates regulator; logic high (≥2V) disables it with <6µA quiescent draw. |
| 2 (VIN) | Main power input | Accepts unregulated 4V–30V supply; must be decoupled with ≥22µF/35V capacitor near pin 2 and pins 5–8. |
| 3 (SW) | Internal NPN switch collector | Drives external inductor and Schottky diode; high dv/dt node requiring short, low-inductance layout. |
| 4 (FB) | Feedback input | Monitors output via resistive divider; internal 1.23V reference sets regulation point - not used in fixed 5.0V variant. |
| 5–8 (GND) | Power and signal ground | Shared thermal and electrical ground path; all four pins must connect to large copper area for thermal management. |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated voltage-mode control | Eliminates external compensation network - simplifies design and ensures stability with standard 68µH inductor and 220µF output capacitor. |
| Power-SOP-8 thermal architecture | Pins 5–8 and die paddle form unified thermal path - achieves 20°C/W junction-to-case resistance for 1A continuous operation. |
| 2.1A minimum current limit | Supports 2A pulsed GSM battery charging without external current-sense circuitry or FET upgrades. |
| Frequency foldback under short-circuit | Reduces switching frequency from 200kHz to ~60kHz during hard shorts - limits power dissipation and prevents thermal runaway. |
| Ultra-low shutdown current | 6µA typical when VSHDN = VIN - enables >1-year battery shelf life in always-on portable chargers. |
Applications
| Cellular Phone Battery Charger | Industrial 5V Point-of-Load Supply |
|---|---|
Use Scenario: Charging Li-ion batteries in dual-mode (GSM/TDMA) handsets with pulsed 2A charge profiles and tight voltage tolerance. IC Role / Device Role / Timing Role: Primary buck regulator providing regulated 5.0V output with fast transient response to handle burst-mode load steps. Use Value: Delivers 4.2V/2A pulsed output within GSM charging specs while maintaining <2% output deviation and <100mV ripple. | Use Scenario: Generating stable 5V rail from 12–24V industrial bus for PLC I/O modules, sensors, and microcontrollers. IC Role / Device Role / Timing Role: Fixed-output DC-DC converter replacing linear regulators or TO-220 buck solutions to reduce heat and board space. Use Value: Achieves 85–90% efficiency at 1A, cutting power loss by >75% vs. linear regulators and enabling compact, fanless enclosure designs. |
| Positive-to-Negative Inverting Buck-Boost | Legacy System Voltage Translation |
Use Scenario: Generating –12V/150mA from +12V supply in telecom line-card interfaces requiring isolated negative bias. IC Role / Device Role / Timing Role: Core switching controller in inverting buck-boost topology - SW pin drives inductor to GND, FB senses inverted output. Use Value: Enables single-chip negative rail generation without transformers or charge pumps - reduces BOM count and improves reliability over discrete solutions. | Use Scenario: Upgrading obsolete 7805-based supplies in field-deployed medical or test equipment where PCB redesign is prohibited. IC Role / Device Role / Timing Role: Drop-in replacement for TO-220 5V LDOs - same 5.0V output but with higher efficiency, wider input range, and built-in protection. Use Value: Extends system lifetime by eliminating thermal bottlenecks and adding overcurrent/thermal shutdown - no layout changes required beyond input/output capacitor relocation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2678-5.0 | 5V fixed, 100kHz switching, requires external compensation, higher quiescent current (5mA active, 50µA shutdown). | Lower switching frequency eases EMI filtering but limits power density; less suitable for GSM pulse loads due to lower current limit (3.5A typ). | Select LM2678-5.0 only if legacy design reuse or lower-frequency EMI compliance is prioritized over efficiency and pulsed-current capability. |
| TPS54202D | 5V fixed, 500kHz, integrated MOSFETs, 2A continuous, 2.5µA shutdown, requires external compensation. | Higher frequency allows smaller magnetics but demands tighter layout; lacks built-in current foldback and has narrower input range (4.5–28V). | Choose TPS54202D when board space is critical and thermal headroom exists; avoid for high-pulse GSM loads unless validated for 2A burst current. |
Compared with LM2678-5.0 and TPS54202D, the MIC4681-5.0BM offers superior pulsed-current handling (2.1A min limit), lower shutdown current (6µA), and factory-compensated operation - making it optimal for space-constrained, battery-powered GSM chargers where simplicity and burst-load reliability are essential.
Availability
MIC4681-5.0BM is available at Aetrix Electronics and suitable for cellular phone battery chargers, industrial 5V point-of-load supplies, and legacy system voltage translation requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for MIC4681-5.0BM 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 Semiconductor (acquired by Microchip in 2015) was a U.S.-based analog and power IC designer known for high-performance DC-DC converters, timing devices, and interface solutions.
The MIC4681-5.0BM belongs to Micrel's SuperSwitcher™ family - engineered specifically for high-efficiency, low-component-count buck conversion in portable and battery-powered systems demanding robust pulsed-current performance and thermal resilience.
FAQ
What is the output voltage tolerance of the MIC4681-5.0BM over temperature and line/load conditions?
The MIC4681-5.0BM delivers a fixed 5.0V output with ±2% tolerance across –40°C to +125°C junction temperature, 4V–30V input, and 0.1A–1A load range. This is confirmed by Electrical Characteristics tables showing 4.95V–5.05V output under full operating conditions, with minimal drift (<±0.02V) versus temperature per typical curves.
Can the MIC4681-5.0BM be used in a GSM battery charger application requiring 2A pulsed output?
Yes - the MIC4681-5.0BM is explicitly characterized for GSM battery charging, sustaining 4.2V/2A pulsed output in typical charging environments. Its 2.1A minimum current limit, fast transient response, and frequency foldback under overload make it suitable for burst-mode Li-ion charging without external current amplification.
Does the MIC4681-5.0BM require external compensation components?
No - the MIC4681-5.0BM features fully internal frequency compensation optimized for stability with standard 68µH inductors and 220µF output capacitors. Bode plots on page 9 confirm >53° phase margin across all input voltages, load currents, and temperatures - eliminating the need for external RC networks.
How should the ground connections be implemented for optimal thermal performance of the MIC4681-5.0BM?
Pins 5–8 of the MIC4681-5.0BM must be connected to a minimum 6 cm² copper ground plane on the PCB - distributed across any layer but with low-impedance thermal vias to inner ground layers. This configuration achieves the specified θJA = 63°C/W and supports 1A continuous operation at 25°C ambient.
What protection features does the MIC4681-5.0BM include, and how do they behave during fault conditions?
The MIC4681-5.0BM includes cycle-by-cycle current limiting (2.2–4.5A), thermal shutdown (~160°C), and frequency foldback during short circuits (reducing to ~60kHz). During overload, it enters hiccup mode - latching off after repeated foldback cycles until SHDN is toggled or input is cycled - preventing damage without external supervision.
MIC4681-5.0BM 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):
- 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
MIC4681-5.0BM FAQ
1.How can I place an order for MIC4681-5.0BM through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC4681-5.0BM 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 MIC4681-5.0BM reliable?
The price and inventory of MIC4681-5.0BM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC4681-5.0BM is usually 5 days.
3.What payment methods are accepted for MIC4681-5.0BM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC4681-5.0BM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC4681-5.0BM?
MIC4681-5.0BM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC4681-5.0BM 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 MIC4681-5.0BM?
For technical support, including MIC4681-5.0BM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC4681-5.0BM requirements.
6.How does Aetrix verify that MIC4681-5.0BM is sourced from the original manufacturer or authorized distributors?
All MIC4681-5.0BM 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 MIC4681-5.0BM meets industry standards.
7.What is the process for return or replacement of MIC4681-5.0BM?
All MIC4681-5.0BM units undergo pre-shipment inspection (PSI). If there is an issue with MIC4681-5.0BM, 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 MIC4681-5.0BM part is unused and in its original packaging.
Return procedure for MIC4681-5.0BM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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