| RefDes | Nodes | Refs | Model | Param | Symbolic | Numeric |
|---|---|---|---|---|---|---|
| C1 | N001 N003 | C | value | $C_{A}$ | $6.3 \cdot 10^{-12}$ | |
| C2 | N002 N001 | C | value | $\frac{C_{A}}{2}$ | $3.15 \cdot 10^{-12}$ | |
| I1 | N001 N002 | I | value | $0$ | $0$ | |
| dc | $0$ | $0$ | ||||
| dcvar | $0$ | $0$ | ||||
| noise | $\frac{4 T k}{R_{B}}$ | $\frac{1.657 \cdot 10^{-20}}{R_{B}}$ | ||||
| I1_XU1 | N001 0 | I | noise | $S_{i}$ | $0$ | |
| I2 | N002 out | I | value | $0$ | $0$ | |
| dc | $0$ | $0$ | ||||
| dcvar | $0$ | $0$ | ||||
| noise | $\frac{4 T k}{R_{o}}$ | $3.314 \cdot 10^{-22}$ | ||||
| N1_XU1 | N002 0 3_XU1 0 | N | ||||
| R1 | out 0 | R | value | $R_{\ell}$ | $50.0$ | |
| R2 | out N002 | R | value | $R_{o}$ | $50.0$ | |
| R3 | N002 N001 | R | value | $R_{B}$ | $R_{B}$ | |
| V1 | N003 0 | V | value | $0$ | $0$ | |
| dc | $0$ | $0$ | ||||
| dcvar | $0$ | $0$ | ||||
| noise | $0$ | $0$ | ||||
| V1_XU1 | N001 3_XU1 | V | noise | $S_{v}$ | $0$ |
| Name | Symbolic | Numeric |
|---|---|---|
| $C_{A}$ | $6.3 \cdot 10^{-12}$ | $6.3 \cdot 10^{-12}$ |
| $R_{\ell}$ | $50$ | $50.0$ |
| $R_{o}$ | $50$ | $50.0$ |
| $S_{i}$ | $0$ | $0$ |
| $S_{v}$ | $0$ | $0$ |
| $T$ | $300$ | $300.0$ |
| $k$ | $1.381 \cdot 10^{-23}$ | $1.381 \cdot 10^{-23}$ |
| Noise source: I1 | ||
|---|---|---|
| Spectral density: | $\frac{1.657 \cdot 10^{-20}}{R_{B}}$ | $\,\mathrm{\left[\frac{A^2}{Hz}\right]}$ |
| Detector-referred: | $\frac{7.017 \cdot 10^{5} R_{B}}{6.636 \cdot 10^{4} R_{B}^{2} f^{2} + 1.694 \cdot 10^{26}}$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Source-referred: | $\frac{10.57}{R_{B} f^{2}}$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ | Noise source: I1_XU1 |
| Spectral density: | $0$ | $\,\mathrm{\left[\frac{A^2}{Hz}\right]}$ |
| Detector-referred: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Source-referred: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ | Noise source: I2 |
| Spectral density: | $3.314 \cdot 10^{-22}$ | $\,\mathrm{\left[\frac{A^2}{Hz}\right]}$ |
| Detector-referred: | $\frac{1.374 \cdot 10^{-14} R_{B}^{2} f^{2} + 3.508 \cdot 10^{7}}{6.636 \cdot 10^{4} R_{B}^{2} f^{2} + 1.694 \cdot 10^{26}}$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Source-referred: | $\frac{2.071 \cdot 10^{-19} R_{B}^{2} f^{2} + 528.7}{R_{B}^{2} f^{2}}$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ | Noise source: V1 |
| Spectral density: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Detector-referred: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Source-referred: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ | Noise source: V1_XU1 |
| Spectral density: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Detector-referred: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
| Source-referred: | $0$ | $\,\mathrm{\left[\frac{V^2}{Hz}\right]}$ |
$R_B$ increases the noise at low frequencies. A show stopper value is obtained if its contribution at the lowest frequency of interest (10kHz) is just within specifications. Hence, we need to solve $R_B$ from:
\begin{equation} 1.0 \cdot 10^{-14}=\frac{7.017 \cdot 10^{5} R_{B}}{6.724 \cdot 10^{11} \pi^{2} R_{B}^{2} + 1.694 \cdot 10^{26}} + \frac{1.374 \cdot 10^{-6} R_{B}^{2} + 3.508 \cdot 10^{7}}{6.724 \cdot 10^{11} \pi^{2} R_{B}^{2} + 1.694 \cdot 10^{26}} \end{equation}in this way we obtain:
\begin{equation} R_{B min}=1.057 \cdot 10^{7} \end{equation}Go to RB_Noise_index
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Last project update: 2022-04-01 16:59:05