Summary generated by the author through intelligent technology. Everyone knows that voltage can be positive or negative.

In electronic circuit applications, it is often necessary to establish a negative voltage, such as when using operational amplifiers.

Main points of this article:

What is negative voltage

How is negative voltage generated

Significance of negative voltage generation

Analysis of the application of negative voltage

What is negative voltage?

In relation to the chosen reference, we can directly explain that when the actual voltage is lower than the reference voltage, the voltage value is negative. The voltage obtained will vary depending on the reference point chosen.

So, what is generally used as the reference point?

The answer is the negative pole of the power supply.

Therefore, the power supply voltage is Vcc=E positive - E negative.

So how is negative voltage generated?

Starting from the reference point of the negative pole of the power supply (assumed to be 0), to generate negative voltage, the potential relative to the negative pole of the power supply is lower. If you want it to be even lower, you need to add another power supply (2). In the figure below, the positive pole of power supply (2) is connected in series with the negative pole of the reference point power supply, and the negative pole of power supply (2) is the negative voltage. This actually utilizes the principle of series connection of two power supplies (doesn't it sound familiar?).

So, what is the significance of generating negative voltage?

1. Avoids large current damage to test equipment and electronic components caused by electron accumulation

Electrons generally carry negative charges and flow towards the positive voltage direction, i.e., the high potential end, forming a current. In the process of using negative voltage, due to the presence of negative charges, too many electrons will accumulate at the ground end of the power supply, reducing the risk of current convergence on the test equipment and subsequent damage or burnout.

2. Helps to some extent in avoiding electromagnetic interference

Negative voltage is helpful for system testing of microampere-level or even smaller-level signals, which can improve the accuracy of test resistors and enhance the ability to resist electromagnetic interference.

3. Compared to positive voltage, negative voltage has better safety performance for human bodies and electronic products

For example, in the telephone system, a voltage of -48V is generally used for power supply, which can avoid telephone line electrochemical corrosion.

Finally, from the perspective of significance, let's talk about the application of negative voltage:

1. Telecommunications industry: Industry standards generally require a power supply of -48V, which can reduce system noise and interference;

2. MOSFET gate control voltage: Negative voltage is used when turning off to help speed up the discharge of capacitors (Miller effect);

3. Dual-power operational amplifier: As mentioned earlier, dual-power supply is used, but in circuit design, it mainly depends on the characteristics of the input signal to see if the signal can be amplified and output normally.

Well, that's all for today's knowledge. Can you please like and follow if you've read this far? Your support is greatly appreciated! Thank you!

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