| ??? 08/26/05 08:37 Read: times Msg Score: 0 +1 Good Answer/Helpful -1 Answer is Wrong |
#100124 - not good idea Responding to: ???'s previous message |
hi,
Peter Dannegger said:
To drive a transistor, put the base direct on the 8051 port pin and a resistor from base to VCC.
...and it will work with pins of port 0 only. With others ports you have a good chance to burn base-emitter of transistor each time when there is 0-to-1 transition on a pin. Why? Because strong pull-up pFET1 is turned on for 2 osc. periods. Read http://www.8052.com/forum/read.phtml?id=93728 Here is corrected schematic by Michael: http://www.8052.com/forum/read.phtml?id=93726 Regards, Oleg |
| Topic | Author | Date |
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| LED Driver - My Solution | 01/01/70 00:00 | |
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| MCU-resistor-NPN | 01/01/70 00:00 | |
| 8051 is open drain ! | 01/01/70 00:00 | |
| not good idea | 01/01/70 00:00 | |
| totally wrong ! | 01/01/70 00:00 | |
| This I would take with a grain of salt. | 01/01/70 00:00 | |
| But nevertheless totally unsuited! | 01/01/70 00:00 | |
| Where in Atmel errata or other informati | 01/01/70 00:00 | |
| That's standard performance of quasi bi. | 01/01/70 00:00 | |
| Try This | 01/01/70 00:00 | |
updated | 01/01/70 00:00 |