Semiconductor Photodiode Capacitance Calculator
Budget measured depletion geometry and independently measured parallel stray capacitances per photodiode, not an abrupt-silicon doping default or one plate capacitor.
Description
A photodiode capacitance budget includes the depletion region and parallel stray capacitance.
A photodiode capacitance budget includes the depletion region and parallel stray capacitance.1
Combining measured geometry with matched permittivity produces a conditional electrical model for each detector.
When to use Semiconductor Photodiode Capacitance Calculator
Use this tool when you need to calculate the stated measurement summary or conditional model from matched observations. Prepare independently matched device or specimen measurements, units, branch selection, and model or calibration conventions.
How to use Semiconductor Photodiode Capacitance Calculator and understand its results
- Prepare independently matched device or specimen measurements, units, branch selection, and model or calibration conventions.
- Enter observedPhotodiodeActiveAreasM2, callerMatchedPermittivitiesFM, observedDepletionDepthsM, observedParallelStrayFarads, following the field table and calculation rules below, then run the tool.
- Read modeledPhotodiodeTotalCapacitancesFarads. Use the output table and calculation rules below to interpret units, signs, crossings, and flags.
- Correct any input issues and run again. Before using a successful result, review its units, signs, evidence coverage, and stated model or reference assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedPhotodiodeActiveAreasM2 | Observed photodiode active areas m2 | list of number | Required |
| callerMatchedPermittivitiesFM | Caller matched permittivities f m | list of number | Required |
| observedDepletionDepthsM | Observed depletion depths m | list of number | Required |
| observedParallelStrayFarads | Observed parallel stray farads | list of number | Required |
Use four nonempty aligned lists. Active areas and stray capacitances may be zero; permittivities and depletion depths must be positive. Compute the geometric depletion capacitance for each entry and add its independently measured parallel stray capacitance.
Ctotal_i=area_i×permittivity_i/depth_i+Cstray_i Read these symbols with the field meanings and branch or reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modeledPhotodiodeTotalCapacitancesFarads | Modeled photodiode total capacitances farads | list of number |
{
"input": {
"observedPhotodiodeActiveAreasM2": [
0.000001,
0.000002
],
"callerMatchedPermittivitiesFM": [
1e-10,
1e-10
],
"observedDepletionDepthsM": [
0.000001,
0.000002
],
"observedParallelStrayFarads": [
1e-11,
2e-11
]
},
"output": {
"modeledPhotodiodeTotalCapacitancesFarads": [
1.1000000000000001e-10,
1.2e-10
]
}
}Limitations and assumptions
Measurements, branch identification, units, and model applicability must be independently established. Results do not supply universal material constants, a complete physical model, or operating-condition approval.
Missing required fields, unknown fields, wrong types, and violated calculation rules return input issues. Numeric values must be finite; nonfinite numeric outputs are rejected. Arrays must be dense, with no missing cells. Numeric lists allow at most 10000 entries, subject to smaller tool-specific bounds above.
Alternative or Complementary methods
For a related task, use Semiconductor Photodiode Bandwidth Calculator: Detector bandwidth can be limited by both resistance-capacitance response and carrier transit. An inverse-square combination is an explicit approximation that requires a separately established transit limit. For a complementary step, use Semiconductor Organic Substrate Dielectric Constant Calculator: A substrate capacitance measurement includes fixture contributions that should be independently assessed. Removing that contribution before inverting the plate model exposes signed calibration discrepancies rather than hiding them.
References
Similar or alternative tools
- Semiconductor Photodiode Bandwidth Calculator
Detector bandwidth can be limited by both resistance-capacitance response and carrier transit. An inverse-square combination is an explicit approximation that requires a separately established transit limit.
- Semiconductor Organic Substrate Dielectric Constant Calculator
A substrate capacitance measurement includes fixture contributions that should be independently assessed. Removing that contribution before inverting the plate model exposes signed calibration discrepancies rather than hiding them.