STTH112U

Diodes - Rectifiers - Single: STTH112U Application Field and Working Principle

The STTH112U is a Silicon FAST recovery diode. It is commonly used in high frequency switch mode power supplies in order to convert an AC voltage into a pulsed DC voltage, as well as to switch high frequency AC power circuits and to protect against lightning and power surges. This diode features excellent current surge handling capability, a high power dissipation of 2.5 W, non-polarity protection, and high surge capability.

Application Field

The STTH112U is well-suited for a wide range of applications, from computer hardware to industrial machinery. It is particularly useful for high power or high frequency power supply applications due to its excellent current surge handling capability and non-polarity protection. It is also excellent protection against lightning and power surges.

Working Principle

The STTH112U consists of two silicon PN-junctions arranged in tandem. The one junction is connected in forward direction and conducts in only one direction, while the other junction is connected in reverse direction and conducts in the opposite direction. The STTH112U characteristics are best understood in terms of its forward voltage drop, reverse breakdown voltage, and charge storage. The forward voltage drop is the voltage across the diode when current flows through it in the forward direction. The reverse breakdown voltage is the voltage at which the current suddenly increases when voltage is applied in the reverse direction. The charge storage is the ability of the diode to store and hold an electrical charge.

When a forward bias voltage is applied to the diode, the current starts to flow from anode to cathode and the diode is said to be in the forward-bias state. The forward voltage drop occurs when the forward bias is applied and current starts to flow. When a reverse bias voltage is applied to the diode, the current is initially zero and the voltage increases until it reaches a certain value and tends to breakdown, owing to the internal field-effect in the PN junction. As the reverse bias voltage increases, the current suddenly increases and the reverse breakdown voltage is reached. The charge storage capability of the diode is determined by its junction capacitance and therefore, the amount of energy it can store is related to its capacitance.

In summation, the STTH112U is an excellent diode for high power or high frequency power supply applications due to its excellent current surge handling capability and non-polarity protection. It is easy to use and requires no special attention during assembly. It is also capable of providing protection against lightning and power surges.