The HM3407B is a HeroMicro P-channel MOSFET fabricated using advanced trench technology, offering ultra-low on-resistance (RDS(ON)), low gate charge (Qg), and excellent thermal performance. It is ideal for low-voltage power applications such as battery management, load switching, and DC-DC converters. Housed in a compact SOT-23 package, it saves board space while maintaining good thermal dissipation.
1. Key Electrical Characteristics (TA = 25°C)
Drain-Source Voltage (VDS): -30 V
Continuous Drain Current (ID):
-4.1 A (at TA = 25°C)
-2.7 A (at TA = 100°C, derated at high temperature)
Pulsed Drain Current (IDM): -16.4 A (limited by max junction temperature)
On-Resistance (RDS(ON)):
Typ. 42 mΩ (max 55 mΩ) @ VGS = -10 V, ID = -4 A
Typ. 62 mΩ (max 85 mΩ) @ VGS = -4.5 V, ID = -3 A
Total Gate Charge (Qg): 6.8 nC @ VGS = -10 V, VDS = -15 V
Gate Threshold Voltage (VGS(th)): -1.0 V to -2.5 V (@ ID = -250 μA)
Power Dissipation (PD): 1.51 W (at TA = 25°C)
Thermal Resistance (RθJA): 83 °C/W
Operating Junction Temperature: -55°C to +150°C
Package: SOT-23 (marked “3407B”)
2. Typical Applications
High-side load switches (e.g., USB power control, battery-powered devices)
Power path management in portable electronics
Reverse polarity protection circuits
Switching or synchronous rectifier in low-power DC-DC converters
Logic-level compatible P-channel switching (supports -4.5V drive)
3. Design Considerations
Gate Drive Voltage:
For minimal conduction loss, drive with VGS ≤ -10 V.
When driven directly by a microcontroller (e.g., 3.3V or 5V logic), connect the gate to GND (VGS = -3.3V or -5V). RDS(ON) will increase to ~70–90 mΩ—verify power dissipation accordingly.
Thermal Management:
The SOT-23 package has a high RθJA (83°C/W). At 1W dissipation, the junction temperature rises 83°C above ambient.
Use ≥2 mm² copper area on drain and source pads to improve heat spreading.
For continuous operation, limit current to ≤2.5 A (at TA = 25°C) to avoid overheating.
Switching Speed & EMI:
Low Qg (6.8 nC) enables fast switching (td(on) = 14 ns, td(off) = 19 ns).
In high-speed applications, add a 10–100 Ω gate resistor to suppress ringing and EMI.
Body Diode Characteristics:
The intrinsic body diode has a typical forward voltage (VSD) of -0.8 V at IS = -4.1 A.
Suitable for freewheeling, but reverse recovery parameters are not specified—avoid in high-frequency hard-switching applications.
Reliability:
Compliant with green (RoHS) standards.
All parameters are measured with ≤300 μs pulses (duty cycle ≤2%). Continuous operation requires derating.
4. PCB Layout Recommendations
SOT-23 Pinout (top view, marking facing up):
Pin 1: G (Gate)
Pin 2: S (Source)
Pin 3: D (Drain)
Connect the source (S) directly to the system ground or battery positive (in high-side configuration).
Widen the drain (D) trace to handle load current.
Keep the gate trace short and avoid running it parallel to high dV/dt nodes to minimize noise coupling.
