BZX85C18-T50R

The BZX85C18-T50R diode is a single Zener diode which is used to regulate voltages in circuits. It is a three-terminal device which is medium power, low leakage and low noise. The device is used for applications such as voltage regulation, surge protection, over-voltage protection and reverse polarity protection. This diode has a rated power dissipation of 500 milliwatts and a forward current rating of 0.3 amperes.

This diode is available in a SOD323 package and it is classified as a 5.6 volt zener diode. Additionally, it has an operating junction temperature range of -55 °C to +150 °C. The BZX85C18-T50R is also characterised by a maximum reverse leakage current of 10 μA and a maximum zener impedance of 250 Ohms. Its power dissipation capabilities depend upon thermal dissipation properties including temperature dependence, thermal resistance and position within the package.

The main purpose of the BZX85C18-T50R diode is to provide protection from over-voltage. It is the main component in an over-voltage protection circuit, which is designed to prevent damage to a device in case of an unexpected and dangerous increase of voltage. The diode is connected in series to a resistor, usually in a parallel circuit where the path of least resistance is the diode. When a predetermined voltage is exceeded, the diode will start conducting current and prevent the increased voltage from reaching the circuit.

Apart from over-voltage protection, this diode can also be used in circuits requiring reliability and stability. The diode can be used to provide voltage regulation by protecting the circuit from over-voltage and under-voltage. Additionally, the diode can protect against reverse polarity where, in the event of a reversal of polarities, the diode will redirect the current flow, thereby providing some level of protection.

The working principle of the BZX85C18-T50R diode is similar to that of a regular diode. It functions as a one-way valve, allowing current to flow only in one direction. However, unlike a regular diode, it has an additional feature which is the breakdown voltage. This is the threshold voltage at which the diode begins to conduct current and is usually specified as a tolerance range of ±5%. The breakdown voltage is responsible for providing the protection as it limits the maximum voltage entering the circuit.