Common Gate Amplifier

Transcription

1 mmn Gate Ampler Fure (a) shs a cmmn ate ampler th deal current surce lad. Fure (b) shs the deal current surce mplemented by PMOS th cnstant ate t surce vltae. DD DD G M G M G M (a) (b) Fure. mmn ate ampler.

2 . L Frequency Small Snal Equvalent rcut D G D - v s S m v s mb v bs ds S - (a) D G D - v s S m mb S ds - (b) Y YL Z (c) Z Fure. mmn ate ampler l requency small snal equvalent crcut.

3 Fure (a) and (b) sh the l requency small snal equvalent crcut. Fure ( c) shs the t-prt, ts prt varables assnment are as lls: Y L ds (r Z v L s, r ds ); Y S (r Z S 0) Frm Fure (b), the current equatns are derved t btan thr Y parameters: m mb ( - ) ( m mb ) - ( m mb) ( - ) ( m mb ) The crrespndn Y-parameter matrx s, ( Y - ( dety 0 m m mb mb ) ) The nput mpedance cmmn ate ampler s, y YL ds ds Z dety yyl 0 ( m mb ) ds m ds m Ths nput mpedance s l, snce m s lare. The utput mpedance cmmn ate ampler s, y Y S Z dety y YS y Ths utput mpedance s hh, snce s very small. A cmmn ate ampler s prmary used as mpedance transrmer rm l t hh mpedance. The vltae an cmmn ate ampler s, A 0 y y Y L m mb ds ( m here : R ut ZO//ZL ds Ths vltae an s practcally the same as the cmmn surce ampler, except r n snal nversn. The current an cmmn ate ampler s, A y YL dety y Y ( m 0 ( ) mb mb ds L m mb ) ds )R ut m R ut 3

4 . Hh Frequency Small Snal Equvalent rcut DD G M d db d G M db L s bs Fure 3. mmn ate ampler parastc capactances. Fure 3 shs all the parastc capacatnces needed r hh requency mdel. Fure 4(a) shs the hh requency small snal equvalent crcut cmmn ate ampler. The t-prt assnment s shn n Fure 4(b). The netrk current equatn s: ( m ( m mb The crrespndn Y-parameter matrx s: m mb s Y - ( m mb ) s dety ( s )( s m s[ ) s mb ) mb ( m ( mb ( - ) ( - ) s ) ] s m ( ) ( m m mb mb mb s ) - ) ( ) s ) 4

5 G D D S v s m mb ds S S - s bs d db d db L (a) Y G L S Z (b) Fure 4. mmn ate ampler hh requency small snal equvalent crcut. The nput mpedance s ven by: y YL Z dety y Y s[ ( ( m mb ds The utput mpedance s ven by: L ) s[( m ( mb ds ds ) ( ) s ( ) ] s m s ) mb ds ( m mb ) ] s s ) ds 5

6 Z O y YS dety y Y S y s The vltae an s ven by: A ( m y - y mb s Y R L ut ( )R m ut mb s A 0 s p ) ds ( m mb ds ) s The banddth s dened by the dmnant ple p. That s, p -3db R ut p π The an banddth s ven by: A 0 ( m mb )R ut R ut ( m mb ) π The phase marn PM r the nn-nvertn ampler, hch the case here, s the dstance the phase anle at the unty an (r 0db) requency () t 80. That s, 6

7 A(j A 0 A( s) s p 0 - tan PM 80 - tan ) 80 PM A( s) A - - p p j p PM 80 - tan 80 - tan - PM 80 - tan The transer snal s a snle ple th n zer. The PM s alays reater 90. Hence t s stable. - (A 0 ) - (A 0 ) mmn Gate Ampler Experments 3. mmn Gate Ampler Basn and L Frequency Small Snal Parameters Determnatn. The D r lare snal transer characterstc s dcult t btan analytcally. The reasns are the ate t surce vltae and the threshld vltae chanes th the nput vltae. Frm Fure, these vltaes are ven by: GS BS G SS - - nstead btann the cmplete D transer characterstc, nly the bas pnt r peratn pnt s nterest. The peratn pnt shuld le n the ren hen bth transstrs are n saturatn. The al s t btan the upper and ler bund the saturatn ren. M, the PMOS transstr n Fure s n saturatn hen the cndtn s satsed. GSP - TP < DSP G - DD - TP < O - DD 0- DD - - < O - DD DD -< DD - O O < M, the NMOS transstr n Fure s n saturatn hen: 7

8 GSN - TN < DSN G - TN < O - G < O TN GSN - TN >0.3 G - TN >0.3 G >0.3 TN ; at bas pnt 0 That s,.3 < G < ths dene the rane G hen G0 t uarantee that bth transstr are n saturatn, select say G.5. Wth ths value selected PSpce smulatn s cnducted t determne the actual peratn pnt, the bas vltae the nput snal. ntally the PSpce le smply enter a uess value the bas vltae. Ths bas ll aect the A respnse but nt the D respnse. The bas vltae s btaned by selectn a pnt at the mddle the steepest slpe. The smulatn shs that ths bas vltae s Ths nrmatn s entered n the PSpce le and re-run t btan the prper A respnse. The peratn pnt and small snal parameters are determned as lls: The threshld vltae s cmputed at the peratn pnt as lls: BS TN B T0 - S γ ( SS - φ BS.5 (.4903).0097 φ ) ( 0.6 (.0097) 0.6).4909 The peratn pnt current s W 9.6E - 6 β 87.7E - 6 N K N 40E - 6 L N (5.4 -)E - 6 DSQ N P βn βn (GSN - TN ) (G E - 6) (.5 (.4903).4909) 98.uA The transcnductances and resstances are cmputed: TN ) 8

9 r R Z A A m mb ds ut R (R ( db r r ds m ( mn ON m φ //R 0l β.964e E - 6 ON γ mb 0 N BS OP mb N λ (A DSQ ).545E6.545M ds DSQ m (.0)((98.E - 6) ) ds )R ut ) 0l (87.7E - 6)(98.E - 6) 0.6 (.0097) ( )E - 6 ( )E - ( )E - 6(.545E6) 47 0 (47) db (30.95E - 6).509E6.509M rds R OP.509E6 λ (.0)((98.E - 6) P DSQ The PSpce smulatn shs that Z.03x0 4 Z.543x0 5 A v db E umh.509M 5.765E - 6 6(.964E - 6) 5.765umhA.08E4 *PSpce le r NMOS mmn Gate Ampler th *PMOS urrent Lad *Flename"Lab3.cr" N 0 D OLT A DD 3 0 D.5OLT SS 4 0 D -.5OLT G 5 0 D.5OLT G 6 0 D 0OLT M 5 4 MN W9.6U L5.4U M MP W5.8U L5.4U.MODEL MN NMOS TO KP40U GAMMA. 0 LAMBDA0.0 PH0.6 TOX0.05U LD0.5U J5E-4 JSW0E-0 U0550 MJ0.5 MJSW0.5 GSO0.4E-9 GDO0.4E-9. MODEL MP PMOS TO- KP5U GAMMA0.6 LAMBDA0.0 PH0.6 TOX0.05U LD0.5U J5E-4 JSW0E-0 U000 MJ0.5 MJSW0.5 GSO0.4E-9 GDO0.4E-9 9

10 *Analyss.D N TF () N.A DE 00 HZ 0GHZ.PROBE.END ()/N 4.894E0 NPUT RESSTANE AT N.03E04 OUTPUT RESSTANE AT ().543E05 0

11 4. mmn Gate Ampler Hh Frequency Mdel Experments The parastc capactances ll be determned t check the thery aanst Pspce smulatn results. The capactances are determned at the peratn pnt. The reverse bas are rst calculated. Fr PMOS, BD B - D DD - O (entered as neatve PMOS plarty are reversed) BS 0 Fr NMOS BDB-DSS-O * BSB-SSS--.5-(-.4903) * O0.56 s the utput vltae at peratn pnt. The MATLAB prram s nvked t btan the parastc capactances. Fr NMOS, [GS,GD,BD,BS]cap(9.6,5.4,-3.06,-.0097) GS3.704F GD3.84F BD9.3375F BS43.44F Fr PMOS, [GS, GD,BD,BS]cap(5.8,5.4,-.94,0) GS6.539F GD0.3F BD F BS5.0F n the rst Pspce smulatn, nly the s and d are ncluded. That s, the utput capactance s calculated as ll: d d 3.84F 0.3F4.6F

12 The theretcal bandth s calculated as lls: R π ( (.545E6)(4.6E -5) ut O 77.49E E6 44E9 44M π mb ) ( )E E9 4.6E -5 m O 3.04E9.077E9.077G π π E9 PM 80 - tan 80 tan E6 The Pspce smulatn results are : -3db PM M.779G T nclude the eect all the parastc capactances. The area and permeter the surce and dran each transstr are ncluded n the PSpce netlst. The utput capactance s re-calculated t nclude all the parastc capactances. O ( )F F d π ( R 44E6 7E9 7M π mb ) ( )E E -5 m db O d db (.545E6)(88.999E -5) ut O.075E E M π π E9 PM 80 - tan 80 tan E9 L 44E6.075E9 The Pspce smulatn results are:

13 6.6343M M PM 9.69 *PSpce le r NMOS mmn Gate Ampler th *PMOS urrent Lad *Flename"Lab3.cr" N 0 D OLT A DD 3 0 D.5OLT SS 4 0 D -.5OLT G 5 0 D.5OLT G 6 0 D 0OLT M 5 4 MN W9.6U L5.4U AD40.3P AS40.3P PD7.6U PS7.6U M MP W5.8U L5.4U AD08.36P AS08.36P PD60U PS60U.MODEL MN NMOS TO KP 40U GAMMA.0 LAMBDA0.0 PH0.6 TOX0.05U LD0.5U J5E-4 JSW0E-0 U0550 MJ0.5 MJSW0.5 GSO0.4E-9 GDO0.4E-9.MODEL MP PMOS TO- KP5U GAMMA0.6 LAMBDA0.0 PH0.6 TOX0.05U LD0.5U J5E-4 JSW0E-0 U000 MJ0.5 MJSW0.5 GSO0.4E-9 GDO0.4E-9 *Analyss.D N TF () N.A DE 00 HZ 0GHZ.PROBE.END 3

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