| ??? 10/01/09 17:52 Read: times |
#169345 - LM339 input bias current Responding to: ???'s previous message |
The LM339 input bias current (approx 25nA) has to flow somewhere other than into C7. You also need a way to discharge C7 when the signal disappears, so I would suggest a 1Mohm resistor connected between the LM339 input and a bias voltage of perhaps 4V. This means that it would take a 0.5V signal to reach the 4.5V comparitor threshold, and the decay time constant is 1 msec. |
| Topic | Author | Date |
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| ? | 01/01/70 00:00 | |
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Absolutely! | 01/01/70 00:00 | |
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