Infineon BSP171PH6327XTSA1: Key Features and Application Circuit Design
The Infineon BSP171PH6327XTSA1 is a state-of-the-art small-signal P-channel MOSFET housed in a compact SOT-23 package. This device is engineered for low-voltage, high-efficiency applications, making it an ideal choice for system designers focused on power management, load switching, and interface control in space-constrained electronic products.
Key Features
One of the most significant attributes of the BSP171P is its exceptionally low threshold voltage (VGS(th)), typically as low as -0.8 V. This feature is crucial for compatibility with modern microcontrollers and logic circuits that operate at lower supply voltages, enabling direct drive without the need for additional level-shifting circuitry.
The MOSFET boasts a low on-state resistance (RDS(on)) of just 500 mΩ (max) at VGS = -4.5 V. This low resistance minimizes conduction losses, leading to higher overall system efficiency and reduced heat generation. Furthermore, the device offers a continuous drain current (ID) of -1.7 A, providing robust performance for a wide range of switching tasks.
Its enhanced ESD protection (up to 2 kV HBM per AEC-Q101) ensures high reliability and robustness in harsh environments, making it suitable for automotive and industrial applications. The SOT-23 package also provides a small footprint, which is essential for modern, miniaturized PCB designs.
Application Circuit Design: Load Switch
A primary application for the BSP171P is as a high-side load switch. This configuration is commonly used to power subsystems on and off in battery-operated devices, helping to conserve power and manage energy effectively.
A typical application circuit is straightforward yet highly effective:
1. The source (S) is connected to the power rail (e.g., a 3.3V or 5V supply).
2. The drain (D) is connected to the load (e.g., a sensor, motor, or LED module).
3. The gate (G) is controlled by a microcontroller (MCU) GPIO pin.
To ensure proper and reliable switching:
A pull-up resistor (e.g., 100 kΩ) is often placed between the source and the gate. This ensures the MOSFET remains off (open circuit) by default when the MCU pin is in a high-impedance state during startup or reset.
A gate-series resistor (e.g., 10 - 100 Ω) is recommended to dampen any ringing caused by parasitic inductance and to limit peak current from the MCU pin, protecting the driver.
For very fast switching speeds or in environments with high noise, a small capacitor (e.g., 1 nF) between the gate and ground can be added to improve stability, though it will slightly increase the switch's turn-on/off time.
Operation: To turn the load ON, the MCU drives its GPIO pin to a logic low (0 V). This pulls the gate voltage below the source voltage, turning the P-Channel MOSFET on and allowing current to flow to the load. To turn the load OFF, the MCU sets its pin to a logic high (or high-impedance), allowing the pull-up resistor to bring the gate voltage equal to the source voltage, thereby turning the device off.
This simple circuit provides solid-state reliability, fast switching, and virtually zero power consumption when in the off state, which is paramount for battery life.
The Infineon BSP171PH6327XTSA1 is a highly efficient and robust P-channel MOSFET that excels in power management roles. Its combination of low threshold voltage, low RDS(on), and strong ESD protection in a miniature package makes it an outstanding solution for designing compact, efficient, and reliable load switch circuits in portable and automotive electronics.
Keywords:
1. P-Channel MOSFET
2. Load Switch
3. Low Threshold Voltage
4. Application Circuit
5. Power Management
