Infineon 2N7002DWH6327 Dual N-Channel MOSFET: Key Specifications and Application Circuit Design
The Infineon 2N7002DWH6327 is a popular dual N-channel enhancement mode MOSFET housed in a space-saving SOT-363 (SC-88) package. It integrates two independent, electrically isolated MOSFETs, making it an ideal solution for compact circuit designs where board space is at a premium. This component is widely used in a variety of low-power switching applications, from consumer electronics to industrial control systems.
Key Specifications
Understanding the critical parameters of the 2N7002DWH6327 is essential for effective circuit design. Below are its key specifications:
Drain-Source Voltage (VDS): 60 V. This defines the maximum voltage that can be applied between the drain and source when the MOSFET is in its off-state.
Continuous Drain Current (ID): 115 mA per MOSFET. This is the maximum continuous current each channel can handle.
Gate-Threshold Voltage (VGS(th)): Typically 1.3 V at 250 µA of drain current. This is the minimum gate-to-source voltage required to create a conducting path between the drain and source. Its relatively low value makes it compatible with 3.3V and 5V logic levels from microcontrollers and other digital ICs.
On-Resistance (RDS(on)): Typically 7.5 Ω at VGS = 4.5 V and ID = 50 mA. A low RDS(on) is crucial as it minimizes power loss and voltage drop across the MOSFET when it is switched on.
Package: SOT-363 (SC-88). This very small footprint is designed for high-density PCB layouts.
Application Circuit Design: Logic-Level Signal Switching
A primary application for the 2N7002DWH6327 is interfacing a low-voltage microcontroller (MCU) with a higher voltage load, such as a relay, lamp, or motor. The following describes a typical circuit design for one of the two channels.
Component Selection:
1. Microcontroller (MCU): Provides the logic-level control signal (e.g., 3.3V or 5V).
2. MOSFET: Infineon 2N7002DWH6327 (one channel used).
3. Load (e.g., a small DC motor or relay coil): Connected in series with the drain pin and the power supply (VLOAD which can be up to 60V).
4. Flyback Diode (if driving an inductive load like a relay or motor): A diode (e.g., 1N4148) placed in reverse bias across the inductive load is critical to protect the MOSFET from voltage spikes generated when the current is suddenly switched off.
5. Gate Resistor (RG): A small resistor (e.g., 100Ω) in series with the gate is often used to dampen ringing and oscillations caused by parasitic inductance and the MOSFET's gate capacitance.
Circuit Operation:
1. When the MCU output is LOW (0V): The gate-to-source voltage (VGS) is 0V, which is less than the threshold voltage VGS(th). The MOSFET is in its cut-off region, acting as an open switch. No current flows through the load.
2. When the MCU output is HIGH (3.3V/5V): VGS rises well above the threshold voltage, pushing the MOSFET into its saturation region. It acts as a closed switch, allowing current to flow from the drain to the source, thus powering the load.
Design Considerations:
Logic Level Compatibility: The 2N7002DWH6327's low threshold voltage ensures it can be fully turned on by typical MCU GPIO pins, making a driver circuit unnecessary for these low-current loads.
Heat Dissipation: For the specified current levels, power dissipation (P = ID2 RDS(on)) is typically low enough that a heatsink is not required. However, calculations should always be verified for the specific application.
ESD Protection: The device is sensitive to electrostatic discharge. Proper ESD handling procedures should be followed during assembly.
In summary, the Infineon 2N7002DWH6327 offers a compact and efficient solution for managing two low-power load circuits. Its integration of two MOSFETs saves significant PCB space, while its logic-level compatibility and robust electrical characteristics make it a versatile choice for designers. When implementing this IC, careful attention to protection against inductive voltage spikes and proper gate driving techniques will ensure reliable and long-lasting circuit operation.
Keywords: Dual N-Channel MOSFET, Logic-Level Gate Drive, SOT-363 Package, Low-Power Switching, Application Circuit Design
