Oriental Semiconductor MOSFETs

Oriental high-voltage MOSFETs (500V-900V) are designed for AC-DC power supplies, LED drivers, and PFC applications where blocking high voltages is required. They feature super-junction technology for low RDS(on) at high voltage ratings. Low-voltage MOSFETs (20V-200V) are optimized for DC-DC converters, synchronous rectification, and battery-powered applications where low RDS(on) and fast switching are critical. Low-voltage devices can achieve much lower RDS(on) (sub-milliohm) compared to high-voltage devices. Choose high-voltage MOSFETs for AC input applications

select low-voltage MOSFETs for DC-DC conversion and high-current applications.

Use high-voltage MOSFETs for AC-DC applications; use low-voltage MOSFETs for DC-DC and high-current applications.

All Oriental MOSFETs have an integral body diode (also called parasitic diode) formed by the p-n junction between the source and drain. This diode can conduct current when the drain voltage goes below the source voltage. The body diode can be used for freewheeling in bridge configurations, but has relatively slow reverse recovery which can cause switching losses and EMI. For high-frequency applications, consider adding an external Schottky diode in parallel or using synchronous rectification with active control. The body diode current rating is typically the same as the MOSFET channel current rating.

Body diode can be used for freewheeling at low frequencies. Add external Schottky for high-frequency applications.

Oriental MOSFETs have specified avalanche energy ratings (EAS) indicating how much energy they can absorb in avalanche mode. However, repetitive avalanche should be avoided as it degrades device reliability. Protection methods include: Using snubber circuits to limit voltage spikes

Selecting MOSFETs with adequate voltage margin (typically 30-50% above normal operating voltage)

Implementing active clamping circuits

Ensuring proper PCB layout to minimize parasitic inductance

Using TVS diodes for overvoltage protection. If avalanche operation is unavoidable, ensure total avalanche energy is within the device's EAS rating and junction temperature stays within limits.

Use snubbers and adequate voltage derating to avoid avalanche. Select MOSFETs with sufficient EAS rating if avalanche is expected.

Threshold voltage (Vgs(th)) is the gate-source voltage at which the MOSFET begins to conduct. For Oriental MOSFETs, Vgs(th) is typically 2-4V, but the device is not fully enhanced at this voltage. To achieve rated RDS(on), a higher gate voltage is required - typically 10V for standard MOSFETs and 12-15V for logic-level devices. Operating with insufficient gate voltage results in high RDS(on) and excessive power dissipation. Always drive MOSFETs with the recommended gate voltage from the datasheet. The threshold voltage has a negative temperature coefficient, meaning it decreases as temperature increases.

Drive MOSFETs with 10-12V gate voltage for full enhancement. Do not rely on threshold voltage for operation.

N-channel MOSFETs require positive gate voltage to turn on and have lower RDS(on) compared to P-channel devices of the same size, making them more efficient for high-current applications. P-channel MOSFETs require negative gate voltage and are typically used as high-side switches where ground-referenced drive is convenient. Oriental primarily offers N-channel MOSFETs for power applications due to their superior performance characteristics. For high-side switching with N-channel devices, a bootstrap or isolated gate drive circuit is required.

Use N-channel MOSFETs for best performance; use P-channel only when ground-referenced drive is essential.