How to Determine the Identification of MOSFET

By Charles Poole

MOSFET transistors are used in a variety of electronics to regulate electricity throughout the device. If you have a MOSFET transistor that needs to be replaced, you will need to identify the transistor before you can put an order in for a replacement. You don't have to be an electrical engineer to identify your transistor -- use the part number and an identification chart for the replacement. There are two kinds of transistors: enhancement transistors increase the voltage to a device, while depletion transistors decrease the voltage to a device.

Step 1

Determine if the transistor is an enhancement or depletion mode transistor. All MOSFET enhancement transistors come from the n-channel series. The p-channel resistors are depletion mode transistors. Look to the bottom of the transistor for an "N-CH" or a "P-U" labeling to determine which type of transistor you need.

Step 2

Determine the voltage rating of the transistor. Look at the bottom of the transistor for the voltage rating. You should see "120V" or something similar.

Step 3

Identify the series of the transistor. All MOSFET transistors use letter series at the beginning of the part number. For instance, the BU series has a "BU" at the beginning of the part number.

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