Diodes - Zener - Single: SZ1SMB5931BT3G application field and working principle

A single Zener diode is a silicon semiconductor device with a uniquely designed PN junction. It is usually just a junction of two layers of N-type and P-type semiconductor materials. The Zener diode is generally used for voltage regulation, but its wide variety of applications range from power supply regulation, to noise suppression and clamping.

The SZ1SMB5931BT3G is a single Zener diode of the SMB type. The SZ1SMB5931BT3G has a maximum current of 125mA and a maximum surge current of 350mA. It has a breakdown voltage range of 5.1V - 5.4V, a thermal resistance of 15°C/W and a power dissipation of 750 mW. This Zener diode is ideal for applications such as power supply regulation, DC impedance regulation, reverse leakage protection, switching-mode power supply, etc.

Working Principle

When the positive voltage applied to the anode is greater than the breakdown voltage of the diode, it will become forward biased. This allows current to flow through the diode and the voltage across its terminals will remain at the breakdown voltage.

The Zener diode reverse characteristics are normally linear in the Zener region, implying that the ratio of ΔVz/ΔIz within the Zener region remains constant.In power applications, the Zener diode is used in series to other components so that it can provide a reference voltage across the series.

Also, a Zener diode can also protect against overvoltage transients. In this application, the Zener diode is connected between the power supply voltage and ground. When a transient voltage occurs, the diode conducts and dissipates the excess energy.

Conclusion

The SZ1SMB5931BT3G is a Zener diode which offers a variety of applications including power supply regulation, DC impedance regulation, reverse leakage protection, switching-mode power supply and transient voltage protection. Its breakdown voltage range sits at 5.1V - 5.4V and it offers a maximum current of 125mA and a maximum surge current of 350mA.