INTL 3:770/1 3:770/3   
   REPLYADDR cl@isbd.net   
   REPLYTO 3:770/3.0 UUCP   
   MSGID: <9qjq7k-sk32.ln1@esprimo.zbmc.eu> 29fa7b6c   
   PID: SoupGate-Win32 v1.05   
   When you power down a Pi is there any simple way to protect inputs   
   which are being driven by externally powered equipment?   
      
   I have A2D devices on the I2C bus which are powered from the Pi, if   
   the Pi has power removed the A2D's will be unhappy I think as their   
   inputs will still have the voltages they are measuring applied to   
   them.   
      
   Similarly I may have one or two logic inputs which are driven by   
   external signals (to see if things are turned on for example) and   
   these inputs will still be there (at 3.3v logic levels) when the Pi is   
   powered down.   
      
   Would diode clamps to the Pi's 3.3v supply be OK or are there better   
   ways?   
      
   --   
   Chris Green   
   ·   
      
   --- SoupGate-Win32 v1.05   
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)   
   SEEN-BY: 10/0 1 15/0 90/1 103/705 105/81 106/201 128/260 129/305 135/225   
   SEEN-BY: 153/757 7715 218/0 1 601 700 840 870 930 220/70 221/1 6 226/17   
   SEEN-BY: 226/30 100 227/114 229/110 112 113 200 206 307 317 400 426   
   SEEN-BY: 229/428 470 550 616 664 700 240/1120 266/512 267/800 282/1038   
   SEEN-BY: 291/111 292/854 301/1 113 812 310/31 320/219 322/757 335/364   
   SEEN-BY: 341/66 342/200 396/45 460/58 633/280 712/848 770/1 3 100   
   SEEN-BY: 770/330 340 772/210 220 230 5020/400 1042 5058/104 5075/35   
   PATH: 770/3 1 218/840 221/6 301/1 218/700 229/426