What is the process of phase compensation technology?

乱世煮酒论天下

What is the process of phase compensation technology? [Copy link]

What are the common phase compensation techniques?

1. Add simple hysteresis capacitor compensation, sacrificing bandwidth in exchange for stability

2. Adding Miller capacitors for compensation requires small capacitance, which is suitable for integrated circuits

3. Add resistors and capacitors to compensate, add a zero point to the transfer function to eliminate a pole. This method sacrifices less bandwidth

4. Adding capacitors to the feedback loop, that is, introducing a leading phase in F(jw) to offset the lagging phase of A(jw), thereby achieving the purpose of improving stability.

What is the reason for this phase compensation? Are phase compensation and frequency compensation the same thing? A book says they are the same, but Baidu says they are different? And how to design and control this phase compensation? Is there any filtering involved in phase compensation?

Found on the Internet: Frequency compensation and phase compensation are both commonly used techniques in signal processing, but they are not the same . Frequency compensation refers to the correction of the amplitude response of the signal so that the signal is evenly amplified or compressed over the entire frequency range. Phase compensation refers to changing the phase of the signal at a specific frequency so that multiple signals can achieve better results when they converge at a certain moment.

maychang

[Find it on the Internet: Frequency compensation and phase compensation are both commonly used techniques in signal processing...]

Half or even more than half of the things on the Internet are nonsense. This requires you to have the ability to distinguish which ones are nonsense, which ones are questionable, and which ones may be correct.

maychang

[How to design and control this phase compensation, and is filtering accompanied by phase compensation? ]

Phase compensation must be accompanied by filtering . In fact, a series of filtering circuits form a phase compensation circuit.

You need to first understand the amplitude-frequency characteristics and phase-frequency characteristics of the first-order RC circuit, referred to as the amplitude-frequency and phase-frequency characteristics, including the first-order low-pass and first-order high-pass. Not only list the formulas, but also draw the amplitude-frequency and phase-frequency curves and clearly understand the characteristics of the amplitude-frequency curve and the phase-frequency curve. The formula is easy to calculate, but the curve is more helpful for intuitive understanding. Then understand what zeros and poles are. Then understand the second-order circuit, especially the LC circuit. Then figure out how to design a compensation circuit based on the compensation characteristics you need.

乱世煮酒论天下

maychang posted on 2024-6-17 08:51 [How to design and control this phase compensation, and is filtering accompanied by phase compensation? ] Phase compensation must be accompanied by filtering. In fact, it is...

For a first-order low-pass filter, the transfer function is H(w)=1/(1+jwRC). The amplitude-frequency curve is the absolute value of this complex number, and the phase-frequency characteristic curve is the tangent angle of this transfer function. Or this complex number is expressed as a+jb, the amplitude-frequency characteristic curve is the square root (a^2+b^2), and the phase-frequency characteristic curve is arctan (b/a).

maychang

Luan Shi Zhu Jiu Lun Tian Xia published on 2024-6-17 11:59 First-order low-pass filter, transfer function H(w)=1/(1+jwRC), the amplitude-frequency curve is the absolute value of this complex number, and the phase-frequency characteristic curve is to find out the transfer function of this complex number.

The 4th floor is right.

However, it is only possible to have a deep understanding if you draw it (with the amplitude-frequency and phase-frequency curves using logarithmic coordinates on the horizontal axis and the amplitude-frequency vertical axis also using logarithmic coordinates).

maychang

Luan Shi Zhu Jiu Lun Tian Xia published on 2024-6-17 11:59 First-order low-pass filter, transfer function H(w)=1/(1+jwRC), the amplitude-frequency curve is the absolute value of this complex number, and the phase-frequency characteristic curve is to find out the transfer function of this complex number.

With the amplitude-frequency and phase-frequency curves of the first-order RC circuit mentioned on the 5th floor, consider how to use curves to represent the poles and zeros of the third method in the first post (adding resistors and capacitors to compensate, adding a zero point to the transfer function to eliminate a pole), and what purpose the third method can achieve.

captz

maychang posted on 2024-6-17 08:42 [Found on the Internet: Frequency compensation and phase compensation are both commonly used techniques in signal processing...] Half of the things on the Internet are even...

As a netizen next door said, there are charlatans who are always talking nonsense, and I agree with it.

maychang

captz posted on 2024-6-17 22:45 As some netizens next door said, there are charlatans who always talk nonsense, I agree.