Next: , Previous: Example Circuits, Up: Example Circuits


12.1 Differential Pair

The following deck determines the dc operating point of a simple differential pair. In addition, the ac small-signal response is computed over the frequency range 1Hz to 100MEGHz.

     SIMPLE DIFFERENTIAL PAIR
     VCC  7  0    12
     VEE  8  0    -12
     VIN  1  0    AC 1
     RS1  1  2    1K
     RS2  6  0    1K
     Q1   3  2  4 MOD1
     Q2   5  6  4 MOD1
     RC1  7  3    10K
     RC2  7  5    10K
     RE   4  8    10K
     .MODEL MOD1 NPN BF=50 VAF=50 IS=1.E-12 RB=100 CJC=.5PF TF=.6NS
     .TF V(5) VIN
     .AC DEC 10 1 100MEG
     .END