readme.txt

PIN_DUAL
dual photodiode amp

4pf caps were placed in parallel with the 1M feedback resistors after testing showed that fast moving signals caused a 40KHz oscillation (about 0.1Vpp).  Maxim semiconductor APPLICATION NOTE 5129 explains why oscillations happen, how to stop them, and  how to size the feedback cap for maximum bandwidth:
http://www.maximintegrated.com/app-notes/index.mvp/id/5129