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Proiect CAIF Podina Andrei Cosmin
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Transcript of proiect_caif
Proiect CAIF
Podina Andrei Cosmin
Datele de proiectare:
• LPF: Butterworth, fc-3db=160kHz, amin=17dB, H0=0dB, biquad Multiple Feedback;
• PGA: castig intre 3dB-21dB cu pasul de 3dB, structura cu comutator in afara caii de semnal, banda minima de 350kHZ;
• AO: Miller, cu intrare pe tranzistoare NMOS, n013, cu alimentare intre 0 si 2V.
Alegerea tipului de biquad
• Biquad Multiple Feedback de ordinul 2:
Formule biquad ord 2:
)1
3232(11
R
RRRRCa c
322121 RRCCb c
)32132
(3221
12
)(22 RR
RRR
SRRCCS
RR
SHcc
1
20
R
RH
Valori determinate pentru elementele de circuit:
• R1=R2=158kΩ
• R3=627kΩ
• C2=10pF
• C1=1pF
Caracteristica de modul a FTJ de ord 2
Frequency
1.0Hz 10Hz 100Hz 1.0KHz 10KHz 100KHz 1.0MHz 10MHz 100MHz 1.0GHzDB(v(out)/v(in))
-200
-150
-100
-50
-0
(-17.651m)
(319.108K,-12.365)
(158.229K,-3.0000)
• H0 este de -17m (deci aprox 0dB), frecventa la 3dB=158kHz, amin=-12,36 dB, deci rezulta ca nu este de ajuns un biquad de ord 2 si ca urmare trebuie marit ordinul
Biquad Multiple Feedback de ordin 3:
Formule biquad ordin 3:
• H0=R4R2/R0R1
• a1=2piFcR4C3
• a2=2piFcC1(R2+R3+R2R3/R1)
• b2=(2piFc)^2 C1C2R2R3
Valorile determinate pentru elementele de circuit:
• R4=R0=100kΩ
• R1=R2=480kΩ
• R3=258kΩ
• C2=8p
• C1=1p
• C3=10p
Frequency
1.0Hz 10Hz 100Hz 1.0KHz 10KHz 100KHz 1.0MHz 10MHz 100MHzDB(v(out)/v(in))
-200
-150
-100
-50
-0
(323.959K,-18.769)
(157.687K,-3.0000)(-36.546m)
• H0=-36m
• Fc-3dB=158kHz
• Amin=-18dB
• Toate cerintele sunt indeplinite de unde rezulta ca biquadul dorit este unul de ordinul 3.
Determinarea GBW minim
f(kHz) GBW(MHz) fc-3dB fa=-18,223dB
E1[%] E2[%]
1000 1000 158 670 320 281 0 0
900 900 158 668 320 272 0.001 0.002
500 500 158 646 320 189 0.015 0.028
100 100 158 443 319 459 0.14 0.25
50 50 158 137 318 548 0.33 0.54
40 40 157 981 318 088 0.43 0.68
30 30 157 724 317 330 0.59 0.92
29 29 157 687 317 221 0.6 0.95
28 28 157 650 317 112 0.64 0.989
27 27 157 608 316 991 0.669 1.02
26 26 157 563 316 859 0.69 1.06
Proiectarea amplificatorului operational Miller
Specificatii de proiectare GBW 40 MHz
SR 40 V/us
CL 10pF
PM 60
Vod uzual 200mV
Parametri obtinuti
CM 3.33pF
IM6 753.6 uA
PM 65.21
Tabel PSF
PSF dupa calcul PSF dupa ajustare
W/L ID(uA) Vod(mV) W/L ID(uA) Vod(mV)
M1,M2 7.95 66.6 159.23 22 67.3 159
M3,M4 37.21 66.6 200 37.21 67.3 200
M5 20.16 133.2 200 26.15 135 200
M6 421.06 753.5 200 415 755 200
M7 114.08 753.6 200 143 755 200
M8 7.59 50 200 9.6 50 200
Parametrii AO
Specificatii de proiectare
Parametrii obtinuti dupa proiectare
GAIN (dB) 60 85.189
GBW(MHz >28 30.819
PM (grade) 60 62.85
Caracteristica de modul
Frequency
1.0Hz 10Hz 100Hz 1.0KHz 10KHz 100KHz 1.0MHz 10MHz 100MHzdb(v(out)/v(in))
-50
0
50
100
(30.819M,0.000)
(1.0000,85.189)
Caracteristica de faza
Frequency
1.0Hz 10Hz 100Hz 1.0KHz 10KHz 100KHz 1.0MHz 10MHz 100MHzP(v(out)/v(in))+180
0d
45d
90d
135d
180d
(30.614M,62.685)
Schema amplificator
Schema test amplificator
Schema PGA cu comutator in afara caii de semnal
Corespondenta comutator castig
Castig Comutator inchis
3dB 1.41 SW5 & SW2
6dB 2 SW5 & SW3
9dB 2.81 SW5 & SW4
12dB 4 SW6 & SW1
15dB 5.62 SW6 & SW2
18dB 7.94 SW6 & SW3
21dB 11.22 SW6 & SW4
Valori rezistente obtinute dupa proiectare
• R6=75kΩ• R5=125kΩ• R0=95.25kΩ• R1=16.21kΩ• R2=15.54kΩ• R3=13.5kΩ• R4=50kΩ• R7=50kΩ
Verificare PGA
Castig ideal Castig real THD[%] Eroarea relativa
3dB 1.41 3.0136 2.88 0.45%
6dB 2 6.0457 3.59 0.75%
9dB 2.81 8.996 3.81 0.04%
12dB 4 12.066 5.23 0.55%
15dB 5.62 15.048 3.16 0.32%
18dB 7.94 18.080 3.2 0.44%
21dB 11.22 21.030 3.65 0.14%
Rezultate analiza domeniu timp:1.castig 3dB
Time
0s 4us 8us 12us 16us 20us 24us 28usV(out) V(in)
0V
0.5V
1.0V
1.5V
2.0V
2.Castig 6 dB
Time
0s 4us 8us 12us 16us 20us 24us 28usV(out) v(in)
0V
0.5V
1.0V
1.5V
2.0V
3.Castig 9 dB
Time
0s 4us 8us 12us 16us 20us 24us 28usv(out) v(in)
0V
0.5V
1.0V
1.5V
2.0V
4.Castig 12 dB
Time
0s 4us 8us 12us 16us 20us 24us 28usv(out) v(in)
0V
0.5V
1.0V
1.5V
2.0V
Verificare LPF+PGA1.castig 3dBTHD=5.31
Time
0s 1us 2us 3us 4us 5us 6us 7us 8us 9us 10usv(out)
0.8V
1.0V
1.2V
1.4V
Castig=6dBTHD=5.52
Time
0s 1us 2us 3us 4us 5us 6us 7us 8us 9us 10usv(out)
0.8V
1.0V
1.2V
1.4V
Castig=9dBTHD=5.42
Time
0s 1us 2us 3us 4us 5us 6us 7us 8us 9us 10usv(out)
0.8V
1.0V
1.2V
1.4V
Castig=12dBTHD=5.26
Time
0s 1us 2us 3us 4us 5us 6us 7us 8us 9us 10usv(out)
0.9V
1.0V
1.1V
1.2V
