Discussion Overview
The discussion revolves around the challenge of cancelling out power supply noise in a circuit involving a high voltage resistor (R2) while measuring its noise characteristics. Participants explore circuit configurations and methodologies to achieve this goal, considering the implications of noise sources and bandwidth on measurements.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
- Mathematical reasoning
Main Points Raised
- One participant inquires about the possibility of completely cancelling power supply noise if the circuit is slightly unbalanced, questioning the existence of such a circuit.
- Another participant asserts that no power supply can be completely noise-free, suggesting that if power supply noise is problematic, the measurement methodology should be reconsidered.
- The resistance value of R2 is stated to be 600 Mohms, with a note that this introduces significant thermal noise that must be accounted for in the measurements.
- A participant proposes using a high voltage capacitor in place of R1 to reduce noise, but expresses difficulty in balancing the circuit to eliminate power supply noise while still measuring R2's noise.
- Bandwidth considerations are highlighted, with a participant noting that the bandwidth of interest is crucial for noise measurement, as different supplies may perform differently within specific frequency ranges.
- Concerns are raised about the thermal noise generated by the high resistance of R2, particularly in relation to the bandwidth of the circuit.
Areas of Agreement / Disagreement
Participants generally agree that complete cancellation of power supply noise is not feasible, but there is no consensus on the best approach to mitigate its effects while measuring R2's noise. The discussion remains unresolved regarding specific circuit configurations and methodologies.
Contextual Notes
Participants mention the importance of bandwidth in noise measurements, indicating that different power supplies may introduce varying levels of noise depending on the frequency range of interest. The implications of thermal noise from high resistance components are also noted, suggesting limitations in measurement accuracy.