Toshiba Adds Two Efficient P-Channel MOSFETs to Lineup

When working with power MOSFETs, electrical engineers often use an N-channel device. With a lower on-state channel resistance and greater efficiency, N-channel devices are the favored device for power designers. But, depending on the design demands and specific circuit topology, P-channel devices are important.

Toshiba has added two P-channel power FETs with improvements over previous generation products. 

 

Toshiba’s P-channel MOSFETs. Image used courtesy of Toshiba

 

Toshiba P-Channel MOSFETs

Toshiba’s MOSFET offerings, the XPH8R316MC and XPH13016MC, are designed for automotive use and offer improved packaging. They have an AEC-Q101 qualification. Toshiba optimized the device’s internal structure for reduced resistance and improved the electrical efficiency and heat build-up immunity. 

 

RDS(on) versus temperature of the XPH8R316MC. Image used courtesy of Toshiba

 

A standout feature of these MOSFETs is their improved low drain-source on-resistance. The XPH8R316MC boasts an RDS(on) of just 8.3 mΩ, representing a substantial 25% reduction compared to Toshiba's previous TPCA8123 model. Similarly, the XPH13016MC's 12.9 mΩ RDS(on) is about 49% lower than the TPCA8125. 

The XPH8R316MC is characterized by a -90 A continuous drain current (ID) and a -180 A pulsed drain current (IDP), making it suitable for high-current applications. In contrast, the XPH13016MC, with an ID of -60A and an IDP of -120 A, is tailored for applications requiring slightly lower current capacities. Both devices can operate at a drain-source voltage of -60 V and withstand channel temperatures up to 175°C, ensuring robust performance under a wide range of operating conditions.

 

N-Channel Versus P-Channel MOSFETs

A difference between N-channel and P-channel MOSFETs is that P-channel devices tend to exhibit higher drain-source on-resistance (RDS(on)). This contrast is rooted in the inherent material and physical properties of the semiconductor technology used in these devices.

Silicon, the most commonly used semiconductor material in MOSFET manufacturing, has different mobility rates for electrons and holes, which are the charge carriers in N-channel and P-channel MOSFETs, respectively. Electrons, which serve as charge carriers in N-channel MOSFETs, have higher mobility than holes, the charge carriers in P-channel MOSFETs. This higher electron mobility allows N-channel MOSFETs to conduct electrical current more efficiently, resulting in lower RDS(on) values.

 

The cross-section of a P-channel MOSFET. Image used courtesy of TU Wien

 

Furthermore, the design and fabrication processes also contribute to the higher RDS(on) in P-channel MOSFETs. To achieve the same conductivity level as N-channel devices, P-channel MOSFETs require a larger silicon area or more complex manufacturing techniques, leading to increased resistance. This is because accommodating the lower hole mobility necessitates adjustments in the device structure, often leading to a compromise in on-resistance performance.

The higher RDS(on) of P-channel MOSFETs influences their application in power electronics design. While they are invaluable for certain circuit configurations, such as CMOS logic gates, where P-channel and N-channel devices are used together, designers often prefer N-channel MOSFETs for high-efficiency power conversion applications. Despite this, P-channel MOSFETs remain an essential component in power electronics, particularly in scenarios where circuit topology or specific design requirements dictate their use.

 

Expanding the P-Channel MOSFET Market

With Toshiba’s devices, power designers can access two new P-channel power FETs with greatly improved performance features. While still not as efficient as typical silicon-based N-channel devices, the XPH8R316MC and XPH13016MC devices are both solid steps in the right direction for P-channel solutions.