Introduction to 1n751a

Introduction to 1n751a

• 1n751a is a zener diode which is also referred as highly reliable voltage regulator, mainly used in industrial, commercial, entertainment and computer applications.
• It comes with a very sharp reverse characteristics, which makes it an ideal choice for voltage stabilization applications.
• This zener diode is a p-n junction diode which is capable of conducting in both directions i.e. forward direction and reverse direction.
• However, making it operate in reverse biased condition is little bit tricky because reverse breakdown voltage must be achieved in order to operate it in reverse biased condition.

• One important feature that makes this zener diode ahead of regular diode is that voltage drop across the zener diode doesn't change over a wide range of voltages, which makes it suitable and highly effective for voltage regulation applications.
• This zener diode works in breakdown voltage and is an ideal choice for generating reference voltage.
• Most of the electronic circuits are equipped with this zener diode because it prevents them from over voltage.
• This zener diode comes with 1.5 forward voltage at 200mA and votlage tolerance appears to be 5%. And reverse leakage current is 1 µA at 1 V.
• It features very effective working characteristic and comes with a power of 500 mW.

Working of 1n751a

• Working of this zener diode is quite identical to normal diode with one exception - it conducts in both directions.
• This zener diode acts like a normal diode in forward biased condition.
• It will only allow the conduction in the reverse direction when reverse voltage reaches to the breakdown voltage, allowing the current to flow from cathode to anode.
• Over a wide range of applied voltage, current reaches to maximum point and stabilizes itself after a certain amount of time, making it suitable for using as a voltage stabilizer.

• Zener breakdown effect is the main cause of voltage breakdown. However, it can also occur due to impact ionization. Both mechanism come into play at 5.5 V and come with same feature and don’t need different circuitry for working efficiently. However, temperature coefficient is the main feature where both mechanism differ. Zener effect shows negative temperature coefficient while impact ionization shows positive temperature coefficient. Both effects cancel each other at 5.5 V, helps zener diode achieving the most stable state over a wide range of temperatures.

Applications

1. Voltage Regulator

• When zener diode is connected in parallel with the voltage using reverse biased mode, it will be capable of starting conduction when voltage equals to a breakdown voltage.

• You can see from the figure above that source voltage is applied in parallel with the diode that helps in decreasing the output voltage from its input, keeping the breakdown voltage constant over a wide range of source voltage.
• Constant breakdown voltage takes a vital part in maintaining the stable output voltage, making it unable for input voltage to effect the output voltage.

2. Waveform Clipper

• Zener diode shows a different behavior when it is connected in series.
• It acts as a waveform clipper when connected in series, allowing the waveform to clip from both ends of the cycle i.e. positive end and negative end of the cycle.

• High voltage spikes that can occur at the end of output voltage can also be prevented with the use of zener diode, helping in reshaping the output signal.

3. Voltage Shifter

• Voltage shifting is another feature in which zener diode is good at.
• When it acts as a voltage shifter, it reduces the amount of output voltage equal to the breakdown voltage.