The scenario
You need a stable high-voltage bias for an avalanche photodiode in a light detection system. The circuit must limit current, filter noise, and provide a sense point for photocurrent monitoring.
What is in this drawing
Read the decisions behind it.
01
Use a 200V source with a 100k current-limiting resistor to protect the APD from overcurrent
02
Add a 1k sense resistor from anode to ground to convert photocurrent to a measurable voltage
03
Place a 10n capacitor across the APD to shunt high-frequency noise
Reusable for any reverse-biased APD application, including LIDAR receivers, photon counting, and optical communication front-ends.
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