| ??? 01/29/06 15:51 Read: times Msg Score: +1 +1 Informative |
#108638 - add pullups for OE1\ and OE2\, Resistors Responding to: ???'s previous message |
Hi,
add pullups to get a more defined behaviour if no PC is connected. Some nitpicking: Buff_x_enable should be called Buff_x_enable\ or Buff_x_disable and the Symbol you're using for VCC would traditionally be used for (digital) Ground. If you want a robust device you will also want to add resistors for the lines connecting the (input lines of the) '244 and the PC. Otherwise you risk supplying current to the target via the internal protection diodes of the '244 if the target VCC is not yet there - not necessarily immediately lethal for the '244 but not good either. Greetings, Frieder |
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