1 difpair ckt - simple differential pair
2 * modified from Spice-3 examples
4 *.opt acct list node lvlcod=2 itermin=0 reltol=.01 abstol=1u vntol=.01
5 *>.opt rstray cstray method=euler outwidth=80
6 .option method=gear order=1
8 *.dc vin -0.25 0.25 0.005
10 vin 1 0 sin(0 0.1 5meg) ac 1 dc 0
22 *.model qnl npn(bf=80 rb=100 ccs=2pf tf=0.3ns tr=6ns cje=3pf cjc=2pf
24 .model qnl npn(bf=80 rb=100 va=50 tr=.4)
26 *>.print tran v(4) v(5)
36 *>.plot tran v(5)(2,10)
40 *>.plot ac vm(5)(0,100) vp(5)(-180,180)