1. 1 Analog Circuit Design Lesson 12 Mixer

2. 2 A mixer is a circuit which multiplies two signals and. That is, if the inputs are and, output will be

3. 3

4. 4 M 3 accepts V 2 which is a signal with low frequency, probably human voice signal or music signal. Its amplitude, on the other hand, is rather large. V 1 is a signal with high frequency and small amplitude.

5. 5 mixer.protect.lib 'c:\mm0355v.l' TT.unprotect.op.options post +nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k.paramW1=120u.paramL1=6u M16433nch L='L1'W='W1' m=1.paramW2=120u.paramL2=6u M27533nch L='L2'W='W2' m=1.paramW3=100u.paramL3=2u M33122nch L='L3'W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP40SIN(0v 0.005v 10Meg) ViN05SIN(0v 0.005v 10Meg).tran0.01us10000ns.plotV(6,7) V(4,5).end

6. 6 V1V1 V2V2 V out

7. 7 V 1 =0 V 2 =SIN(-0.98v 0.06v 500k)

8. 8 mixer.protect.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT.unprotect.op.options post nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k R333_30k.paramW1=120u.paramL1=6u M16433 nch L='L1‘ W='W1' m=1.paramW2=120u.paramL2=6u M27533 nch L='L2‘ W='W2' m=1.paramW3=100u.paramL3=2u M33_3122 nch L='L3‘ W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP400 ViN050.tran0.01us10000ns.plotV(3) V(6,3) V(7,3) V(4,3) V(5,3).end

9. 9 V2V2 V DS1 V DS2 V GS1 V GS2

10. 10 mixer.protect.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT.unprotect.op.options post nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k R333_30k.paramW1=120u.paramL1=6u M16433 nch L='L1‘ W='W1' m=1.paramW2=120u.paramL2=6u M27533 nch L='L2‘ W='W2' m=1.paramW3=100u.paramL3=2u M33_3122 nch L='L3‘ W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP400 ViN050.tran0.01us10000ns.plotV(3) I(R1) I(R2) I(R3).end

11. 11 V2V2 I DS1 I DS2 I DS3

12. 12 The above result shows that V 2 causes the VDS ’ s of all transistors to be sinusoidal. Even the VGS ’ s of M 1 and M 2 are now sinusoidal.

13. 13 In the following, we make both V 1 and V 2 sinusoidal. V 1 =SIN(0v 0.005v 10Meg) V 2 =SIN(-0.98v 0.06v 500k)

14. 14 mixer.protect.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT.unprotect.op.options post nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k R333_30k.paramW1=120u.paramL1=6u M16433 nch L='L1‘ W='W1' m=1.paramW2=120u.paramL2=6u M27533 nch L='L2‘ W='W2' m=1.paramW3=100u.paramL3=2u M33_3122 nch L='L3‘ W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP40SIN(0v 0.005v 10Meg) ViN05SIN(0v 0.005v 10Meg).tran0.01us10000ns.plotV(3) V(6,3) V(7,3) V(4,3) V(5,3) V(6,7).end

15. 15 V2V2 V DS1 V DS2 V GS1 V GS2 V out

16. 16 We can see that VDS 1 =V 2 -V 1 and VGS 1 =-(V 2 -V 1 ). VDS 2 =V 2 +V 1 and VGS 2 =-(V 2 +V 1 ). In other words, M 1 and M 2 are influenced by both V 2 and V 1.

17. 17 In the following, we shall display V 6 and V 7.

18. 18 mixer.protect.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT.unprotect.op.options post nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k R333_30k.paramW1=120u.paramL1=6u M16433 nch L='L1‘ W='W1' m=1.paramW2=120u.paramL2=6u M27533 nch L='L2‘ W='W2' m=1.paramW3=100u.paramL3=2u M33_3122 nch L='L3‘ W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP40SIN(0v 0.005v 10Meg) ViN05SIN(0v 0.005v 10Meg).tran0.01us10000ns.plotV(3) V(6) V(7) V(6,7).end

19. 19 V2V2 V6V6 V7V7 V out

20. 20 V6V6 V7V7

21. 21 mixer.protect.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT.unprotect.op.options post nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k R333_30k.paramW1=120u.paramL1=6u M16433 nch L='L1‘ W='W1' m=1.paramW2=120u.paramL2=6u M27533 nch L='L2‘ W='W2' m=1.paramW3=100u.paramL3=2u M33_3122 nch L='L3‘ W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP40SIN(0v 0.005v 10Meg) ViN05SIN(0v 0.005v 10Meg).tran0.01us10000ns.plotI(R1) I(R2) I(R3).end

22. 22 I DS1 I DS2 I DS3

23. 23 Note that With both V 1 and V 2, we have Thus, we have

24. 24

25. 25 mixer5.protect.lib 'c:\mm0355v.l' TT.unprotect.op.options post nomod acct list VDD801.5v VSS20-1.5v R186130k R287130k R333_30k.paramW1=120u.paramL1=6u M16432 nch L='L1' W='W1' m=1.paramW2=120u.paramL2=6u M27532 nch L='L2' W='W2' m=1.paramW3=100u.paramL3=2u M33_3122 nch L='L3' W='W3' m=1 VG210SIN(-0.98v 0.06v 500k) ViP40SIN(0v 0.005v 10Meg) ViN05SIN(0v 0.005v 10Meg).tran0.01us10000ns.plotV(3) V(6,3) V(7,3) V(4,3) V(5,3) V(6,7).end

26. 26 V2V2 V3V3 V DS2 V GS1 V GS2 V out V DS1 V1V1 V DS3

27. 27 V2V2 V DS1 -V 1

28. 28 V2V2 V DS2 V1V1

29. 29 mixer1.PROTECT.LIB "C:\mm0355v.l" TT.UNPROTECT VDD101.5V VSS120-1.5V Rm11165k M11123 3 NCHW=120U L=6U M33412 12 NCHW=100U L=2U V120SIN(0v 0.005v 10Meg) V240SIN(-0.98v 0.06v 500k).plotV(11,3) V(2,3) V(3,12) I(Rm).tran 0.1ns 4us.END

30. 30 V GS1 V1V1 V DS1 V2V2

31. 31 mixer1.PROTECT.LIB "C:\mm0355v.l" TT.UNPROTECT.op VDD101.5V VSS120-1.5V Rm11165k M11123 0 NCHW=100U L=6U M33412 0 NCHW=100U L=6U V120SIN(0v 0.005v 10Meg) V240SIN(-0.95v 0.06v 500k).plotV(11,3) V(2,3) V(3,12) I(Rm).tran 0.1ns 5us.END

32. 32 V2V2 V3V3 V GS1 V DS1 V1V1 V DS3