LISO simulations confirm the estimate of ~15nV for the noise of REFL11.
The largest contribution comes from the 50Ohm output resistor (Rs in the schematic below), the 450Ohm feedback resistor of the max4107 opamp stage; the 10KOhm resistor at the Test Input connector.
See attached plot.
(It's also all in the SVN, under https://nodus.ligo.caltech.edu:30889/svn/trunk/alberto/40mUpgrade/RFsystem/RFPDs/)
#
# gnd
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# Cw2
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# n23
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# Lw2
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# gnd n22
# | |
# Rip Rw2
# | | |\
# nt- Rsi-n2- - - C2 - n3 - - - - | \
# | | | | |4106>-- n5 - Rs -- no
# iinput Rd L1 L2 R24 n6- | / | |
# |- nin- | | | | | |/ | Rload
# Cd n7 R22 gnd | | |
# | | | | - - - R8 - - gnd
# gnd R1 gnd R7
# | |
# gnd gnd
#
#
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