You MAY be able to current sense at lower voltage drops using a long tailed pair using only two (or possibly three) transistors. Also something like an LM358 (dual opamp) or LM339 (quad comparator) is quite cheap - probably around $US0.20 in volume, maybe less.) Having a transistor partially turned on with external bias would also allow lower voltage drop across the sense resistor but complicates the circuit somewhat. Russell McMahon ----- Original Message ----- From: "Alexandre Guimarces" To: Sent: Tuesday, June 18, 2002 9:49 PM Subject: [EE]: Are there any small germanium transistors still being manufactured ? I need lower vbe !! > Hi, > > Does anyone knows about any small signal germanium transistors that are > still in production ???!! > > I need slower vbe than silicon to use in a short circuit protection > system. The 0.6 volts of silicon transistor makes me use a large wire wound > resistor that could have it's value divided by 3 and would also get the > dissipation much lower. For this application the leakage problems should not > make any difference. It is either that or complex op-amps circuits and the > thing has high side drivers wich make it harder to measure current. The > project is very price sensitive so I am not able to use protected FET's. > > Best regards, > Alexandre Guimaraes > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.