Bu Zeng – Huawi:
This week’s study began with single-ended amplifiers, categorized into common source, common gate, and common drain amplifiers. From the perspective of conduction angle, they are further divided intoA、AB、B、C、D、E and other amplifiers. Differential circuits can suppress common-mode noise while achieving larger swing, widely used in circuits. Degradation techniques are also widely applied in circuits; source degeneration input series feedback can enhance the linearity and other characteristics of the circuit. Current mirrors can provide a stable current source for circuits, and in certain high-performance scenarios, thegain boosting technique can further improve the output impedance of the current mirror.
In operational amplifier design,Miller compensation is the most commonly used method to ensure stability, but there exists a feedforwardcap path, which can lead to a zero point in the left half-plane, posing a risk of insufficient stability.
Zhou Ziyang – Suzhou Kaiweite:
The fifth slide mainly discusses several basic functions ofMOS transistors, the relationship between current and gate voltage, transconductance, and impedance,MOS transistors’ various states, such as weak inversion, strong inversion, saturation, linear, deep linear region, etc. It then introduces the typical transfer functions of common source, common gate, and common drain configurations, as well as simplea、b、ab class drivers, and the calculation of zeroes and poles for differential pairs and two-stage operational amplifiers. The impedance isolation of current mirrors andcascode is also detailed, and the derivation ofgain-boosting to enhance gain is discussed in detail, making it suitable for those with a foundation to revisit and discover many details.