• Tech Note on Op-Amps Driving Capacitance

      Tech Note on Op-Amps Driving Capacitance

      A great tech not on OP Amps driving capacitance. http://www.analog.com/library/analogDialogue/archives/31-2/appleng.html Q. How does capacitive loading affect op amp performance? A. To put it simply, it can turn your amplifier into an oscillator. Here's how: Op amps have an inherent output resistance, Ro, which, in conjunction with a capacitive load, forms an additional pole in the amplifier's transfer function. As the Bode plot shows, at each pole the amplitude slope becomes more negative by 20 dB/ decade. Notice how each pole adds as much as -90° of phase shift. We can view instability from either of two perspectives. Looking at amplitude …Read More »
    • New Instrumentation Amp

      New Instrumentation Amp

      We used to build amplifiers for digital scales (weighing Instrumentation)  where we would sample a full scale voltage reference and a ground reference and from there digitally cancel out gain and baseline drift.  Nowadays the amplifier itself can do a lot of this correction.  We used to call these amplifiers “coppers” referring to the processRead More »
    • Join me at VCF East Friday April 17th

      Join me at VCF East Friday April 17th

      I will be doing a workshop this Friday at VCF East on computer architecture. Each year is bigger and better and this is the second year for three days of computer related festivities. Worth the drive if you are in the NJ, NY, PA area!Read More »