I'm using the only model of the LM386 I was able to find on the Web in LTSpice, but discovered that it has a major flaw: the output doesn't sit anywhere near halfway between Vcc and ground. I'd be thrilled anyone has access to a better model, or could explain how to correct this one? Thanks.
- lm386 subcircuit model follows:
************************************original* IC pins: 2 3 7 1 8 5 6 4
- IC pins: 1 2 3 4 5 6 7 8
- | | | | | | | | .subckt lm386 g1 inn inp gnd out vs byp g8
- input emitter-follower buffers:
q1 gnd inn 10011 ddpnp r1 inn gnd 50k q2 gnd inp 10012 ddpnp r2 inp gnd 50k
- differential input stage, gain-setting
- resistors, and internal feedback resistor:
q3 10013 10011 10008 ddpnp q4 10014 10012 g1 ddpnp r3 vs byp 15k r4 byp 10008 15k r5 10008 g8 150 r6 g8 g1 1.35k r7 g1 out 15k
- input stage current mirror:
q5 10013 10013 gnd ddnpn q6 10014 10013 gnd ddnpn
- voltage gain stage & rolloff cap:
q7 10017 10014 gnd ddnpn c1 10014 10017 15pf
- current mirror source for gain stage:
i1 10002 vs dc 5m q8 10004 10002 vs ddpnp q9 10002 10002 vs ddpnp
- Sziklai-connected push-pull output stage:
q10 10018 10017 out ddpnp q11 10004 10004 10009 ddnpn 100 q12 10009 10009 10017 ddnpn 100 q13 vs 10004 out ddnpn 100 q14 out 10018 gnd ddnpn 100
- generic transistor models generated
- with MicroSim's PARTs utility, using
- default parameters except Bf:
.model ddnpn NPN(Is=10f Xti=3 Eg=1.11 Vaf=100
- Bf=400 Ise=0 Ne=1.5 Ikf=0 Nk=.5 Xtb=1.5 Var=100
- Br=1 Isc=0 Nc=2 Ikr=0 Rc=0 Cjc=2p Mjc=.3333
- Vjc=.75 Fc=.5 Cje=5p Mje=.3333 Vje=.75 Tr=10n
- Tf=1n Itf=1 Xtf=0 Vtf=10)
.model ddpnp PNP(Is=10f Xti=3 Eg=1.11 Vaf=100
- Bf=200 Ise=0 Ne=1.5 Ikf=0 Nk=.5 Xtb=1.5 Var=100
- Br=1 Isc=0 Nc=2 Ikr=0 Rc=0 Cjc=2p Mjc=.3333
- Vjc=.75 Fc=.5 Cje=5p Mje=.3333 Vje=.75 Tr=10n
- Tf=1n Itf=1 Xtf=0 Vtf=10)
.ends
*----------end of subcircuit model-----------