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| # Diode breakdown happens when a reverse biased diode is subjected to so much voltage that it conducts in the reverse direction. When a diode is reverse-biased past the breakdown voltage, it stays enters metastable state, in which any at free charge would start an avalanche and make the diode draw so much current that it may damage the diode. | | # Diode breakdown happens when a reverse biased diode is subjected to so much voltage that it conducts in the reverse direction. When a diode is reverse-biased past the breakdown voltage, it stays enters metastable state, in which any at free charge would start an avalanche and make the diode draw so much current that it may damage the diode. |
| # If a resister is placed in the circuit, it prevents the current from getting too high and stops the diode from being fried. To make an avalanche-like pulse, you would also a capacitor that would be connected in parallel to the diode. It serves as a temporary battery that supplies enough current to create an initial breakdown pulse, after which the capacitor is drained and the resister reduces the voltage below breakdown and the breakdown condition is no longer met and the avalanche is self-quenched. | | # If a resister is placed in the circuit, it prevents the current from getting too high and stops the diode from being fried. To make an avalanche-like pulse, you would also a capacitor that would be connected in parallel to the diode. It serves as a temporary battery that supplies enough current to create an initial breakdown pulse, after which the capacitor is drained and the resister reduces the voltage below breakdown and the breakdown condition is no longer met and the avalanche is self-quenched. |
− | # A Photodiode is a diode that is especially sensitive to light. It contains a very thin doped region and a very thick depleated zone in which photons are absorbed. It is usually packaged in a clear glass or plastic case that allows light through to maximize the effect it has upon the diode. | + | # A Photodiode is a diode that is especially sensitive to light. When it is reversed biased, it conducts when it is exposed to light and blocks current when it is in the dark. It contains a very thin doped region and a very thick depleated zone in which photons are absorbed. It is usually packaged in a clear glass or plastic case that allows light through to maximize the effect it has upon the diode. |
| # An avalanche photodiode is a photodiode designed in such a way that it releases a pulse of electrons per photon instead of just one. In the process mentioned beforehand, the avalanche photodiode uses the energy from the photon to throw the photodiode off its metastable state and create a pulse. | | # An avalanche photodiode is a photodiode designed in such a way that it releases a pulse of electrons per photon instead of just one. In the process mentioned beforehand, the avalanche photodiode uses the energy from the photon to throw the photodiode off its metastable state and create a pulse. |
| # Temperatures are caused by vibrations of atoms and a higher temperature would cause more random thermal fluctuations. Some of these thermal fluctuations have enough energy to throw the photodiode off its metastable state also, causing misfiring. | | # Temperatures are caused by vibrations of atoms and a higher temperature would cause more random thermal fluctuations. Some of these thermal fluctuations have enough energy to throw the photodiode off its metastable state also, causing misfiring. |