| ??? 10/09/09 11:56 Read: times |
#169571 - Threshold voltage Responding to: ???'s previous message |
At what size signal do you want to say that the signal is there? With an ideal diode and a bias of 4V you would need a signal amplitude of 0.5001V to exceed the 4.5V comparator trip point. If that's a bit too sensitive for you, a 3.5V bias would bump the minimum detected amplitude up to 1.00001V. When talking about ideal diodes, a Schottky diode is more ideal in this application because it has a lower forward voltage drop. The rectifier forward voltage is dropped between the amplifier output and the comparator input, resulting in reduced sensitivity. |
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