Version 4 SHEET 1 3088 1688 WIRE 1888 912 1792 912 WIRE 2000 912 1888 912 WIRE 1792 928 1792 912 WIRE 2000 928 2000 912 WIRE 1888 976 1888 912 WIRE 1792 1024 1792 1008 WIRE 2000 1024 2000 1008 WIRE 2064 1024 2000 1024 WIRE 2160 1024 2128 1024 WIRE 2240 1024 2160 1024 WIRE 2160 1040 2160 1024 WIRE 2000 1056 2000 1024 WIRE 1792 1104 1568 1104 WIRE 1888 1104 1888 1056 WIRE 1888 1104 1856 1104 WIRE 1936 1104 1888 1104 WIRE 1568 1120 1568 1104 WIRE 1888 1120 1888 1104 WIRE 2160 1136 2160 1120 WIRE 2000 1184 2000 1152 WIRE 2096 1184 2000 1184 WIRE 2000 1200 2000 1184 WIRE 1568 1216 1568 1200 WIRE 1888 1216 1888 1200 WIRE 2096 1216 2096 1184 WIRE 2000 1296 2000 1280 WIRE 2096 1296 2096 1280 FLAG 1792 1024 0 FLAG 1568 1216 0 FLAG 2240 1024 OUT FLAG 2000 1296 0 FLAG 1888 1216 0 FLAG 2096 1296 0 FLAG 2160 1136 0 SYMBOL voltage 1792 912 R0 SYMATTR InstName V2 SYMATTR Value 15 SYMBOL npn 1936 1056 R0 SYMATTR InstName Q1 SYMATTR Value 2N2222 SYMBOL res 1984 912 R0 SYMATTR InstName R3 SYMATTR Value 1K SYMBOL res 1984 1184 R0 SYMATTR InstName R5 SYMATTR Value 100 SYMBOL res 1872 960 R0 SYMATTR InstName R1 SYMATTR Value 75K SYMBOL res 1872 1104 R0 SYMATTR InstName R2 SYMATTR Value 10K SYMBOL cap 1856 1088 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value .1µ SYMBOL cap 2080 1216 R0 SYMATTR InstName C2 SYMATTR Value 10µ SYMBOL res 2144 1024 R0 SYMATTR InstName R4 SYMATTR Value 100K SYMBOL cap 2128 1008 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 1µ SYMBOL voltage 1568 1104 R0 WINDOW 123 40 57 Left 2 WINDOW 39 22 97 Left 2 SYMATTR Value2 AC 1 SYMATTR SpiceLine Rser=1K SYMATTR InstName V1 SYMATTR Value "" TEXT 2120 1336 Left 2 !.noise V(out) V1 oct 10 1K 100K TEXT 1480 1336 Left 2 ;To plot NF vs. Frequency:\n 10*log10(V(inoise)*V(inoise)/(4*k*300.15*1K))\n Note that the units are dB but will be labeled V/sqrt(Hz)\n If you add the line\n .func NF(R) 10*log10(V(inoise)*V(inoise)/(4*k*300.15*R))\n to your plot.defs file, then you can conveniently plot the quantity NF(1K) TEXT 1624 1240 Top 2 ;1K Source Impedance TEXT 1952 1504 Top 1 ;This example schematic is supplied for informational/educational purposes only. RECTANGLE Normal 1776 1280 1488 1072 2