FDY302NZ FDY302NZ Single FETs, MOSFETs 20V 600mA 625mW 1.5V SC-89-3

Onsemi FDY302NZ N-Channel 2.5V Small Signal MOSFETs 20V, 0.6A, 0.3Ω

The FDY302NZ is an N-Channel PowerTrench® MOSFET developed by onsemi / Fairchild Semiconductor, optimized for low-voltage applications requiring high efficiency in minimal space. Designed specifically for Li-ion battery packs, portable electronics, and power management circuits, this MOSFET delivers low RDS(ON) even at reduced Gate-Source voltages (VGS = 2.5V), ensuring minimal conduction losses in battery-powered systems.

Key advantages include:

• Ultra-compact SOT-523-3 package (1.6mm × 0.88mm × 0.78mm) for PCB space-saving designs
• Exceptional efficiency with RDS(ON) = 500mΩ @ VGS=2.5V, ideal for low-voltage MCUs
• Fast switching (turn-on delay: 6ns, fall time: 2.4ns) for high-frequency applications
• Integrated ESD protection enhances reliability

Key Features

✅ Low RDS(ON): 500mΩ @ VGS=2.5V, 300mΩ @ VGS=4.5V
✅ High Current Handling: 600mA continuous drain current
✅ Compact Footprint: SOT-523-3 package (<1.5mm² footprint)
✅ Fast Switching: Turn-on delay: 6ns, ideal for PWM circuits
✅ Robust Protection: ESD-protected gate structure

Specifications

Electrical & Thermal Characteristics

Mechanical & Packaging

Applications

1. Battery-Powered Electronics

• Li-ion Battery Protection Circuits
• Power Management Modules
• Low-Voltage DC-DC Converters

2. Portable & Wearable Devices

• Smartwatches/Fitness Trackers
• Wireless Earbuds
• Medical Wearables

3. Signal & Load Switching

• Load Switches (MCU-driven power control)
• Low-Side Switching Circuits
• USB Power Distribution

4. Fast-Switching Circuits

• PWM Motor Drivers
• LED Drivers
• High-Frequency DC Converters

Why Choose FDY302NZ Over Alternatives?

1. Optimized Performance @ Low VGS
   • Unlike standard MOSFETs requiring ≥4.5V for low RDS(ON), the FDY302NZ operates efficiently at VGS=2.5V, making it ideal for single-cell Li-ion applications.
2. Space-Efficient Design
   • The ultra-small SOT-523-3 package allows placement in cramped PCBs, unlike bulkier SOT-23 alternatives.
3. Reliable & Industry-Proven
   • Built with onsemi’s PowerTrench® technology, ensuring low conduction losses and thermal stability.

Ordering Information

Conclusion

The FDY302NZ is an ultra-efficient, low-voltage N-Channel MOSFET designed for modern battery-powered and portable electronics. With exceptionally low RDS(ON) @ 2.5V, compact packaging, and fast-switching capabilities, it outperforms competing MOSFETs in power-sensitive applications.

Onsemi FDY302NZ Recommended Alternatives

The FDY302NZ (N-Channel PowerTrench MOSFET) has been discontinued and is no longer manufactured by onsemi. For existing designs still requiring replacement or new projects seeking equivalent performance, onsemi recommends the following drop-in compatible alternatives:

Recommended Replacements

Best Alternatives Explained

1. FDV305N (Recommended Direct Replacement)

✅ Closest Match: Similar SOT-23 footprint, lower RDS(ON) (220mΩ)
✅ Higher Current Handling (900mA)
✅ Better Efficiency (~56% lower conduction losses than FDY302NZ)
✅ Drop-in Compatible: Pin-for-pin replacement in most designs

🚀 Best For:

• Li-ion Battery Protection Circuits
• Portable Electronics

2. NTJD4401N (Dual MOSFET Alternative)

✅ Space-Saving Dual-Channel MOSFET
✅ ESD Protection Integrated
✅ Good for Signal Switching

🚀 Best For:

• Battery Management Systems
• Analog Signal Multiplexing

3. NTK3134N (Higher Performance Option)

✅ Low RDS(ON) (350mΩ)
✅ Supports 890mA Drain Current
✅ Single-Channel SC-89 Package

🚀 Best For:

• Low-Side Switching Applications
• Power Management Modules

4. NTNS3164NZ (Ultra-Miniature Option)

✅ Tiny DFN-3 Package (1.0mm × 0.6mm)
✅ Optimized for Wearables

🚀 Best For:

• Medical Patches
• IoT Sensors

Migration Considerations

When transitioning from FDY302NZ to alternative MOSFETs:
🔹 Check PCB Footprint: SOT-523-3 → SOT-23 or DFN-3 may require minor adjustments
🔹 Verify Gate Drive: Some alternatives have lower VGS(th) (e.g., NTJD4401N @ 0.7V)
🔹 Thermal Performance: Higher-current variants (FDV305N) may need thermal vias

While FDY302NZ is obsolete, onsemi offers superior alternatives with better efficiency, smaller packages, and higher current capabilities.

🎯 Recommended Upgrade Path:

1. For Most Designs: Use FDV305N (best balance of RDS(ON) & footprint)
2. For Dual-Channel Needs: Choose NTJD4401N
3. For Ultra-Compact Apps: Consider NTNS3164NZ

Quick Comparison Summary

🔄 FDV305N → Best FDY302NZ replacement (900mA, 220mΩ)
🔌 NTJD4401N → Dual MOSFET (630mA/ch, 375mΩ)
📐 NTNS3164NZ → Smallest (DFN-3, 245mA)