How to Choose a “Powerhouse Heart” for Power Tools? Select the Right Goodwork MOSFET!
As the power tool market continues to evolve, consumers demand greater battery life, performance, and reliability. All of this hinges on the “heart-level” electronic component of power tools: the MOSFET. A suitable MOSFET not only boosts power and runtime but also extends tool lifespan and reduces failure rates.
Today, we present a comprehensive guide to selecting Goodwork MOSFETs for power tool applications—walking you step-by-step through the right component choice!
1. What Exactly Does a MOSFET Do in Power Tools?
1.1. Motor Drive System (Core Function)
Brushed DC Motors: Utilizes H-bridge circuits for forward/reverse operation + precise PWM speed control, effortlessly handling diverse tasks like screwdriving and drilling.
Brushless DC Motors: The core of three-phase six-transistor bridge circuit control, determining the tool’s power response speed and operational smoothness.
Core Requirements: Low on-resistance (Rds(on)), high switching speed, strong surge resistance.
1.2. Battery Management System (BMS, Safety Guardian)
Overvoltage/undervoltage protection (prevents overcharging/overdischarging) and overcurrent/short-circuit protection (rapid circuit disconnection during faults) form the first line of battery safety defense.
Core Requirements: Low static power consumption, high reliability, excellent consistency.
1.3. Charging Circuit (Runtime Assurance)
Handheld low-power tools: High-voltage VDMOS suffices.
High-power tools: Super-junction (SJ) MOSFETs significantly reduce losses and boost charging efficiency.
Goodwork Product Recommendation: Goodwork’s VDMOS and Cool MOS series MOSFETs substantially reduce conduction losses in charging circuits, enhancing efficiency and extending battery life for power tools.
2 Four-Step Selection Process for Precise Matching and Pitfall Avoidance
MOSFET selection shouldn’t be based on intuition. Master these four core parameters to effortlessly solve selection challenges!
2.1. Voltage Parameters: Safety First, Ensure Adequate Margin
l Selection Principle: Breakdown voltage (Vds) ≥ 1.5-2 times the operating voltage.
l Example: 12V battery system → Select models rated 30V or higher.
lKey Logic: Withstands back-EMF and surge voltages during motor start/stop cycles to prevent device breakdown.
2.2. Current Parameters: Performance Foundation, Account for Peak Currents
lRated Current (ID): ≥5-10 times motor rated current.
lPeak Current (IDM): ≥3 times motor rated current (to handle instantaneous startup surges).
lCalculation example: 12V/500W drill → I = 500W/12V ≈ 42A → Select ≥100A rated current.
2.3. On-Resistance (Rds (on)): Efficiency Key, Lower is Better
l Selection Principle: Prioritize models below 10mΩ; recommend under 5mΩ for high-power tools.
l Comparative Insight: A MOSFET with 4.5mΩ vs. 10mΩ reduces power dissipation by 55% at the same current.
2.4. Package Selection: Space and Thermal Considerations
Goodwork Recommendations: Goodwork offers diverse packaging options, including TO-252 for compact tools and SOP8, TO-220, TO-247 for medium-to-large tools, ensuring thermal management and reliability across power levels.
3. Selection Criteria for Different Power Tool Types
Precise selection based on operating conditions maximizes performance for various power tools:
3.1. Drills/Screwdrivers (Most Common)
Operating Conditions: 12-20V voltage, 500-1000W power, peak current 30-50A
Recommendation: N-channel MOSFET, 30-60V breakdown voltage, 60-100A rated current, Rds(on) < 5mΩ, TO-252 package
3.2. Angle Grinders/Cutters (High Power)
Operating Conditions: High inrush current, sustained high current, demanding thermal management
Recommendation: 60V+ voltage rating, 100A+ rated current, Rds(on) < 3mΩ, TO-220/TO-247 package with enhanced thermal dissipation
3.3. Electric Saws/Hammers (Impact Loads)
Core Requirements: Exceptional impact resistance (UIS) + Low Rds(on)
Recommendation: Dedicated high-UIS series products, effortlessly withstand frequent impact conditions
3.4. Electric Wrench (High Torque)
Operating Conditions: Instantaneous high current, short-duration high-intensity operation
Recommendation: Low Rds(on), high current density models, balancing reliability and burst performance
4. Selection Pitfall Avoidance Guide
✅ Do This:
Ensure ample voltage margin: Maintain over 50% derating
Control temperature rise: Keep MOSFET junction temperature below 125°C
Match power to package: Use small packages for low power, enhance cooling for high power
Verify through testing: Evaluate temperature rise and switching waveforms during sampling
❌ Avoid These:
Relying on “just enough” voltage rating
Prioritizing price over Rds(on)
Forcing small packages into high-power applications
Ignoring batch consistency
5.Solid State Selection Recommendations: Efficient & Reliable, One-Stop Solution
Whether for motor drives, BMS protection, or charging circuits, Goodwork’s Cool MOS Series + VDMOS Series precisely match your needs:
l Low Rds(on) design for reduced losses and higher efficiency;
l Comprehensive package coverage for diverse tool sizes;
l Robust surge resistance and high reliability for stable operation under extreme conditions.
Choose Goodwork Technology MOSFETs to deliver stronger power, longer runtime, and extended lifespan for your power tools!