Infineon IRFR2405TRLPBF: N-Channel MOSFET Datasheet and Application Circuit Design Guide
The Infineon IRFR2405TRLPBF is a highly efficient N-Channel power MOSFET utilizing advanced process technology to achieve excellent switching performance and minimal on-state resistance. This device is encapsulated in a compact D-Pak (TO-252-3) package, making it suitable for a wide range of power management applications, including DC-DC converters, motor control, power supplies, and load switching systems.
Key Datasheet Parameters and Characteristics
A thorough understanding of the datasheet is critical for effective circuit design. The following parameters define the operational boundaries and performance of the IRFR2405TRLPBF:
Drain-Source Voltage (VDS): 55V. This specifies the maximum voltage the device can block between its drain and source terminals.
Continuous Drain Current (ID): 12A at TC = 100°C. This is the maximum continuous current it can handle with a specific case temperature.
On-State Resistance (RDS(on)): < 40mΩ (max) at VGS = 10V. This is a crucial figure of merit. A lower RDS(on) translates directly to reduced conduction losses and higher efficiency, as less power is dissipated as heat during the "on" state.
Gate Threshold Voltage (VGS(th)): 2V to 4V. This defines the voltage range at which the MOSFET begins to turn on.
Total Gate Charge (Qg): 16nC (typ). This parameter is vital for designing the gate driving circuit, as it determines the current required from the gate driver to switch the device quickly.
Application Circuit Design Guide
Designing with a MOSFET like the IRFR2405TRLPBF involves more than just connecting it to a load. Key design considerations include:
1. Gate Driving:
A proper gate driver is essential. The driver must be capable of sourcing and sinking the peak current required to charge and discharge the gate charge (Qg) quickly. A gate resistor (e.g., 10-100Ω) is often used in series to control the rise/fall times, dampen ringing, and prevent oscillations. For the IRFR2405TRLPBF, a gate-source voltage (VGS) of 10V is recommended to ensure full enhancement and achieve the lowest possible RDS(on).
2. Switching and Conduction Losses:
Power loss in a MOSFET comes from two primary sources:
Conduction Loss: Calculated by I_D² x RDS(on). Minimized by selecting a MOSFET with low RDS(on) for the application's current.
Switching Loss: Occurs during the transition between on and off states. These losses are proportional to switching frequency. To minimize them, fast switching driven by a capable gate driver is necessary.
3. Thermal Management:
The D-Pak package has a low thermal resistance from junction to case (RθJC) but a higher resistance to the ambient (RθJA). The power dissipated (P_loss = Conduction Loss + Switching Loss) must be managed effectively. For high-current applications, attaching the tab to a sufficient heatsink is mandatory to keep the junction temperature within the specified limit (175°C max).
4. Protection Circuits:
Overcurrent Protection: Implement a current sensing mechanism (e.g., shunt resistor) to monitor drain current and shut down the gate drive if a threshold is exceeded.
Overvoltage Protection: Use TVS diodes or snubber circuits to clamp voltage spikes on the drain node caused by parasitic inductance in the circuit.
ESD Protection: The device has built-in ESD protection, but handling precautions should still be observed.
Example: Simple Switch Circuit
A fundamental application is a low-side switch. The load is connected between the drain and the positive supply (V+), while the source is connected to ground. The microcontroller or logic circuit controls the gate via a gate driver IC. When the gate is driven to 10V, the MOSFET turns on, completing the circuit and powering the load. When the gate is pulled to 0V, the MOSFET turns off.
The Infineon IRFR2405TRLPBF is a robust and efficient N-Channel MOSFET ideal for a multitude of power switching applications. Successful implementation hinges on a deep understanding of its datasheet parameters, particularly RDS(on) and Qg, coupled with prudent design practices focusing on gate driving, thermal management, and circuit protection.
Keywords:
1. MOSFET
2. RDS(on)
3. Gate Charge (Qg)
4. Switching Loss
5. Thermal Management
