Difference between revisions of "Noise Calculations"
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== TES-bias Noise Performance == | == TES-bias Noise Performance == | ||
| + | See [[Bias Card low noise bias lines noise analysis | Noise Analysis of LN_Bias lines in Bias Card ]] | ||
| + | |||
Depending on the mce configuration, a single-ended or differential, a unipolar or bipolar circuit is used to drive the TES bias. Here is some non-accurate(!!) calculation of the estimated noise performance of the TES bias circuitry. (python scrip to be posted...) | Depending on the mce configuration, a single-ended or differential, a unipolar or bipolar circuit is used to drive the TES bias. Here is some non-accurate(!!) calculation of the estimated noise performance of the TES bias circuitry. (python scrip to be posted...) | ||
| Line 22: | Line 24: | ||
! ev<sub>pp</sub>@0.1-10Hz | ! ev<sub>pp</sub>@0.1-10Hz | ||
nV | nV | ||
| − | ! e<sub>n</sub>@1Hz | + | ! e<sub>n</sub>@0.1Hz |
nV/rtHz | nV/rtHz | ||
! e<sub>n</sub>@10kHz | ! e<sub>n</sub>@10kHz | ||
nV/rtHz | nV/rtHz | ||
| − | ! i<sub>n</sub>@1Hz | + | ! i<sub>n</sub>@0.1Hz |
pA/rtHz | pA/rtHz | ||
! i<sub>n</sub>@10kHz | ! i<sub>n</sub>@10kHz | ||
| Line 107: | Line 109: | ||
|100 | |100 | ||
|6.5 | |6.5 | ||
| − | | | + | |13.1 |
|1 | |1 | ||
| − | | | + | |33.3 |
| − | |0. | + | |0.11 |
|1.34 | |1.34 | ||
|- | |- | ||
| Line 126: | Line 128: | ||
|} | |} | ||
| + | |||
| + | ;Where | ||
| + | : '''e<sub>n</sub>''': voltage noise at the output of the op-amp (independent of cable-resistance, etc) | ||
| + | : '''i<sub>n</sub>''': output current noise partially driven from R<sub>path</sub> | ||
| + | : '''e<sub>n-shunt</sub>''': voltage noise at the shunt resistor | ||
| + | |||
| + | [[Category:Bias Card]] | ||
Latest revision as of 16:24, 31 August 2016
Calculating Noise Requirement
TES-bias Noise Performance
See Noise Analysis of LN_Bias lines in Bias Card
Depending on the mce configuration, a single-ended or differential, a unipolar or bipolar circuit is used to drive the TES bias. Here is some non-accurate(!!) calculation of the estimated noise performance of the TES bias circuitry. (python scrip to be posted...)
- Assumptions
- Rshunt = 3.4 m<math>\Omega</math>
- Rcable = 200 <math>\Omega</math>
- Rpath-diff1 = 467<math>\Omega</math>
- Rpath-single1 = 400<math>\Omega</math>
- The reference-voltage noise is not taken into account.
1: path refers to path-resistance in the mce crate
- Legacy opams used as TES bias output circuitry:
| opamp | output type | DAC config | evpp@0.1-10Hz
nV |
en@0.1Hz
nV/rtHz |
en@10kHz
nV/rtHz |
in@0.1Hz
pA/rtHz |
in@10kHz
pA/rtHz |
en-shunt
pV/rtHz |
en-shunt @0.1Hz
pV/rtHz |
|---|---|---|---|---|---|---|---|---|---|
| LT1128C | differential | unipolar | 35 | 1.5 | 0.9 | 15 | 0.9 | 0.12 | 3.06 |
| OPa227U | differential | unipolar | 90 | 6.5 | 3 | 6.5 | 0.4 | 0.12 | 1.36 |
| AD797 | differential | bipolar | 50 | 5.7 | 0.9 | 20* | 2 | 0.46 | 11.24 |
| AD8675 | differential | bipolar | 100 | 6.5 | 2.8 | 1 | <0.3 | 0.30 | 0.79 |
| AD8675 | differential | unipolar | 100 | 6.5 | 2.8 | 1 | <0.3 | 0.12 | 0.38 |
| AD8622 | single-ended | unipolar | 200 | 20 | 11 | 0.25 | 0.15 | 0.09 | 0.36 |
| OP285 | single-ended | unipolar | 100 | 6.5 | 13.1 | 1 | 33.3 | 0.11 | 1.34 |
| OP2227 | single-ended | unipolar | 90 | 6.5 | 3 | 6.5 | 0.4 | 0.06 | 0.75 |
- Where
- en: voltage noise at the output of the op-amp (independent of cable-resistance, etc)
- in: output current noise partially driven from Rpath
- en-shunt: voltage noise at the shunt resistor
