Hi! I implemented the app note dorm figure 7 on a PCB. The differences are: - I have 50 ohm resistors for the conversion crom IA/IB to VA/VB - for the LT1809 difference amp i use your LT5400-3 (gain=10) - i changed by mistake IA and IB , VB goes to Vminus, VA goes to Vplus My Pcb was broken, the output seems to oscilate. By random i put my Finger on the LT5400 And the output like magic appear corectly. I tought that i need a capacitor in the opamp feedback and by mistake i put it between the output and VB, and it worked a time. And now Any time i put my Finger on that capacitor wich is 47 pF the PCB is working. I Tried to put it between Vminus And output But it doesn t work that good. Can you help me please ? It s a part of my degree project witch i am presenting tuesday.
ADI Part Number: LTC1666