Infineon IRFR120NTRLPBF: Key Specifications and Application Circuit Design for Power MOSFETs

The Infineon IRFR120NTRLPBF is a benchmark N-channel power MOSFET that has become a staple in modern electronic power conversion and control systems. Leveraging advanced silicon technology, this component offers an optimal balance of efficiency, robustness, and cost-effectiveness, making it suitable for a wide array of applications from switch-mode power supplies (SMPS) to motor control and DC-DC converters.

Key Specifications

Understanding the critical parameters of the IRFR120NTRLPBF is essential for effective circuit design.

Drain-Source Voltage (V_DS): 100 V. This rating defines the maximum voltage the device can block between its drain and source terminals in the off-state, making it suitable for a variety of low-to-medium voltage applications.

Continuous Drain Current (I_D): 17 A at a case temperature (T_C) of 25°C. This specifies the maximum continuous current the MOSFET can handle. It is crucial to consider derating with increasing temperature.

On-Resistance (R_DS(on)): 32 mΩ (max) at V_GS = 10 V. This is arguably one of the most critical parameters. A low R_DS(on) directly translates to lower conduction losses and higher overall efficiency, as less power is dissipated as heat when the switch is on.

Gate Threshold Voltage (V_GS(th)): 2.0 V to 4.0 V. This is the minimum gate-to-source voltage required to create a conducting path between the drain and source. It is vital for ensuring full enhancement with the chosen drive voltage.

Gate Charge (Q_g): 44 nC (typ). This parameter is key for determining switching performance. A lower gate charge allows for faster switching speeds and reduces the demands on the gate driver circuitry.

Package: D²PAK (TO-263). This surface-mount package offers an excellent power-to-size ratio and provides a low thermal resistance path (R_thJC = 0.5 °C/W) for efficient heat transfer to a PCB copper area or an external heatsink.

Application Circuit Design Considerations

Designing a reliable circuit with the IRFR120NTRLPBF requires attention to several key areas:

1. Gate Driving: To achieve fast switching and minimize transition times (and thus switching losses), a dedicated gate driver IC is highly recommended. The driver must be capable of sourcing and sinking the peak current required to charge and discharge the MOSFET's gate capacitance (Q_g) quickly. A gate resistor (e.g., 10-100Ω) is often used in series to suppress ringing and control the rise/fall time.

2. Protection:

Overvoltage Protection: Transient voltage suppression (TVS) diodes or snubber circuits may be necessary to clamp voltage spikes caused by parasitic inductance in the circuit (e.g., from long leads or PCB traces).

Overcurrent Protection: A sense resistor or other current monitoring circuit should be implemented to protect the MOSFET and the load from fault conditions.

3. Thermal Management: Despite its low R_DS(on), power dissipation (I²R) can still generate significant heat. Proper PCB layout is critical; a large copper pour connected to the drain tab (which is electrically connected to the drain pin) acts as an effective heatsink. For higher power applications, an external heatsink attached to the PCB area is mandatory to keep the junction temperature within safe limits.

4. Example: Simple Switch Circuit

A fundamental application is a low-side switch. The load is connected between the drain and the positive supply rail (V_DD), while the source is connected to ground. The gate driver circuit, controlled by a microcontroller PWM output, switches the MOSFET on and off, thereby controlling power to the load (e.g., a motor or lamp).

ICGOODFIND

In summary, the Infineon IRFR120NTRLPBF is a highly versatile and efficient power MOSFET. Its standout features of a low 32 mΩ on-resistance, a high 17 A current rating, and a 100 V voltage capability make it an excellent choice for designers seeking to optimize performance in power switching applications. Success hinges on a robust design approach that includes a strong gate driver, effective protection mechanisms, and diligent thermal management.

Keywords: Power MOSFET, RDS(on), Gate Driver, Switching Losses, Thermal Management