| ??? 09/03/11 11:21 Read: times |
#183605 - Saturated Switching Transistor Responding to: ???'s previous message |
You really need to look at the timing requirements of the address decoding to determine if a cheap NPN junction type transistor would be suitable to the design. A saturated switching circuit like a 2N3904 can take as much as 200 to 300 nanoseconds to turn on and some longer to turn off including the rise time of the signal due to the pullup resistor. I suspect you would be a lot better off using a small "tiny logic" single gate type inverter part.
If your argument of wanting to use the one transistor is one of cost savings I can only say that the savings seems minuscule against the cost of the main parts you mention in your design (C8051F340 and W5300). Michael Karas |
| Topic | Author | Date |
| A transistor in place of a not gate | 01/01/70 00:00 | |
| Saturated Switching Transistor | 01/01/70 00:00 | |
| Cost | 01/01/70 00:00 | |
| single gate inverter | 01/01/70 00:00 | |
| Invert Your Address | 01/01/70 00:00 | |
| Good suggestion | 01/01/70 00:00 | |
| Not good! | 01/01/70 00:00 | |
Thanks | 01/01/70 00:00 |