MOSFET High-Side Load Switch – Smart Power Control Made Easy
⚠️ The Problem :
When powering loads like LEDs, motors, or sensors, many beginners place a N-channel MOSFET on the low side (between load and ground). But some applications, especially with shared grounds (like microcontrollers), require switching on the high side (between power and load). Standard N-MOSFETs won’t fully turn on in high-side setups unless the gate is driven above the source—this is where P-channel MOSFETs or gate driver circuits come in.
✅ The Solution :
Use a P-channel MOSFET for high-side switching. Connect the source to the supply, the drain to the load, and control the gate with a pull-up resistor and an NPN transistor (or microcontroller pin) that pulls the gate low to turn the MOSFET on.
🔍 Practical Example :
Say you’re controlling a 12V LED strip from an ESP32 (3.3V logic). If you want to switch the +12V line (not ground), a P-channel MOSFET like IRF9540 works perfectly when its gate is pulled low.
🧮 Sample Calculation :
For a 12V, 1A LED strip:
Power = 12V × 1A = 12W
Choose a MOSFET rated ≥ 20V, 2A, ideally with low Rds(on) to reduce heat.
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Pick high-quality, Made in India P-channel MOSFETs for your power control needs:
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