מגברי שרת

✦ בנוי על ידי פהד גאנם ✦

Vin = V+ − V−
Vout = AV·Vin
AV → ∞
0.00 mV
0.00 mV
0.00 mV
0.0 V
0.00 V

Vin = V⁺ − V⁻ = 1.2 − (−0.4) = +1.6 mV
AV·Vin ≈ 200000 · 0.0016 = 320 V  ≫  Vcc
Vin > 0  ⟹  Vout = +Vcc = +9 V

Av = VoutVin = 1 + R2R1
V⁺ = V⁻
i⁺ = i⁻ = 0

3.0 V
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V⁻ = V⁺ = 3 V
i₁ = V⁻R1 = 3 V5 kΩ = 0.6 mA
i₂ = i₁ = 0.6 mA
Vout = V⁻ + i₂·R2 = 3 + 0.6mA·15kΩ = 3 + 9 = 12 V
Av = 1 + R2R1 = 1 + 15 kΩ5 kΩ = 4  →  Vout = 4 · 3 V = 12 V ✓

Av = VoutVin = − RfR1
1.0 V
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V⁻ = V⁺ = 0 V
i = Vin − V⁻R1 = 0.5 V2 kΩ = 0.25 mA
Vout = V⁻ − i·Rf = 0 − 0.25 mA · 18 kΩ = −4.5 V
Av = −4.5 V0.5 V = −9   ✓  − 18 kΩ2 kΩ = −9
−9 · 2 V = −18 V  →  |−18| > 12  →  Vout = −12 V

Vout = Vin
Av = 1
Rin → ∞
Rout → 0
2.0 V
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i = VsRs + RL = 2 V9 kΩ + 1 kΩ = 0.2 mA
VL = i · RL = 0.2 mA · 1 kΩ = 0.2 V
is = 0  →  V⁺ = 2 V  →  VL = Vout = 2 V
iL = VLRL = 2 V1 kΩ = 2 mA

Vout = − Rf · ( V1R1 + V2R2 + V3R3 + … )
R1 = R2 = … = Rf  ⟹  Vout = −(V1 + V2 + V3 + …)
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V⁻ = V⁺ = 0 V
i1 = 2 V10 kΩ = 0.2 mA
i2 = 3 V20 kΩ = 0.15 mA
i3 = −1 V5 kΩ = −0.2 mA
if = i1 + i2 + i3 = 0.2 + 0.15 − 0.2 = 0.15 mA
Vout = 0 − if · Rf = −0.15 mA · 10 kΩ = −1.5 V
Vout = −10 · ( 210 + 320 + −15 ) = −10 · 0.15 = −1.5 V ✓

V+ = V1R1 + V2R2 + …1R1 + 1R2 + …
Vout = ( 1 + RfRg ) · V+
R1 = R2 = … = Rn  ⟹  V+ = V1 + V2 + … + Vnn
1 + RfRg = n  ⟹  Vout = V1 + V2 + … + Vn
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V+ = 210 + 410110 + 110 = 0.60.2 = 3 V
i1 = 2 − 310 kΩ = −0.1 mA
i2 = 4 − 310 kΩ = 0.1 mA
Av = 1 + RfRg = 1 + 1010 = 2
Vout = 2 · 3 = 6 V = V1 + V2 ✓
if = 6 − 310 kΩ = 310 kΩ = 0.3 mA ✓

Vout = − RfR1 · V1 + ( 1 + RfR1 ) · R3R2 + R3 · V2
R1 = R2 , Rf = R3  ⟹  Vout = RfR1 · ( V2 − V1 )
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V+ = V2 · R3R2 + R3 = 6 · 2030 = 4 V
i2 = 6 V30 kΩ = 0.2 mA
V− = V+ = 4 V
i1 = V1 − V−R1 = 2 − 410 kΩ = −0.2 mA
Vout = V− − i1 · Rf = 4 − (−0.2 mA) · 20 kΩ = 8 V
Vout = 2010 · (6 − 2) = 2 · 4 = 8 V ✓

0.01log = −2
0.1log = −1
1log = 0
2log ≈ 0.3
10log = 1
100log = 2
1000log = 3
1,000,000log = 6
log x = — 20 · log x = —

Av[dB] = 20 · log ( VoutVin )
Ap[dB] = 10 · log ( PoutPin )
A = A1 · A2 · A3  ⟹  A[dB] = A1[dB] + A2[dB] + A3[dB]
×0.1−20 dB
×0.5−6 dB
×0.707−3 dB
×10 dB
×1.414+3 dB
×2+6 dB
×10+20 dB
×100+40 dB
×1000+60 dB
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A1 = 1 + 91 = 10
A1[dB] = 20 · log 10 = 20 dB
A2 = − 2010 = −2
A2[dB] = 20 · log 2 = 6.02 dB
A = 10 · (−2) = −20
A[dB] = 20 + 6.02 = 26.02 dB = 20 · log 20 ✓
Vout = −20 · 50 mV = −1 V

VTH = +Vsat · R1R1 + R2
VTL = −Vsat · R1R1 + R2
VTH = +Vsat · R1R2
VTL = −Vsat · R1R2
ΔV = VTH − VTL
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VTH = 12 · 1010 + 20 = 4 V
VTL = −12 · 1010 + 20 = −4 V
ΔV = 4 − (−4) = 8 V
i = 12 V30 kΩ = 0.4 mA
Vin ↑ 4 V ⟹ Vout = −12 V
Vin ↓ −4 V ⟹ Vout = +12 V
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