Infineon BSS223PWH6327 P-Channel MOSFET: Datasheet, Pinout, and Application Circuits
The Infineon BSS223PWH6327 is a robust P-Channel MOSFET housed in a compact SOT-323 surface-mount package. Engineered for low-voltage, high-efficiency switching applications, this component is a popular choice for power management tasks where board space and energy efficiency are critical. Its P-Channel enhancement mode nature allows it to be an ideal high-side switch, often simplifying drive circuitry compared to N-Channel alternatives in certain scenarios.
This article provides a detailed overview of its key specifications, pinout configuration, and typical application circuits.
Datasheet Overview and Key Specifications
The BSS223PWH6327 is characterized by its low threshold voltage and low on-resistance, which are pivotal for minimizing power losses and improving overall system efficiency. Key absolute maximum ratings and electrical characteristics include:
Drain-Source Voltage (VDS): -20 V
Continuous Drain Current (ID): -1.7 A
On-Resistance (RDS(on)): Typically 120 mΩ at VGS = -4.5 V
Gate Threshold Voltage (VGS(th)): Typically -0.95 V (max -1.5 V) at ID = -1 mA
Package: SOT-323, an ultra-small footprint package suitable for high-density PCB designs.
These specifications make it exceptionally suitable for load switching, power management in portable devices, battery protection circuits, and DC-DC conversion modules.
Pinout Configuration
The SOT-323 package has three pins. When viewing the component with the flat edge facing upward, the pinout is as follows:
Pin 1 (Left): Gate (G)
This pin controls the conductivity between the source and drain. A voltage sufficiently negative relative to the source turns the MOSFET on.
Pin 2 (Center): Drain (D)
For a P-Channel MOSFET, this is the terminal through which current exits the device when it is switched on.
Pin 3 (Right): Source (S)
This is the terminal from which current flows into the device. It is typically connected to the positive supply rail in a high-side switch configuration.
Correct pin identification is crucial to prevent device damage during soldering and circuit operation.
Application Circuits
1. High-Side Load Switch
The most common application for a P-Channel MOSFET is as a high-side switch. In this configuration, the source is connected to the power supply (V+), and the load is connected between the drain and ground. A simple push-button or logic signal from a microcontroller (through a suitable resistor) can control the gate. To ensure fast and complete turn-off, a pull-up resistor is often used between the gate and source to hold the gate high (and the MOSFET off) when the control signal is inactive.
2. Reverse Polarity Protection
A P-Channel MOSFET can provide highly efficient reverse polarity protection with a very low voltage drop compared to a traditional diode. The MOSFET is placed in the positive rail with its source toward the power input and drain toward the protected circuit. The gate is pulled to ground through a resistor. Under correct polarity, the body diode is initially forward-biased, allowing current to flow and creating a gate-to-source voltage that turns the MOSFET on, bypassing the diode. If polarity is reversed, the gate-source junction remains unbiased, keeping the MOSFET off and protecting the downstream circuitry.
3. Simple DC-DC Converter (Inverting Buck-Boost)
While more complex than a simple switch, P-Channel MOSFETs can be used in the power stage of certain switched-mode power supply (SMPS) topologies. They act as the main switching element, controlled by a PWM signal from a dedicated IC to regulate the output voltage.
ICGOODFIND Summary
The Infineon BSS223PWH6327 is a highly efficient and compact P-Channel MOSFET solution, prized for its low on-resistance and small SOT-323 package. It excels in applications demanding minimal voltage drop and high switching efficiency in space-constrained environments, such as portable electronics, battery-powered systems, and power management units. Its use as a high-side switch significantly simplifies circuit design, making it a fundamental component for modern electronic design engineers.
Keywords: P-Channel MOSFET, Load Switch, Reverse Polarity Protection, SOT-323, Low On-Resistance
