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E252 - Coggle Diagram

- - - - V- : Input (Inverting)
      - V+ : Input (Non-Inverting)
      - Vo : Output
      - Vcc : DC Supply (positive)
      - VEE : DC Supply (negative or ground)
    - - Infinite Open-Loop Voltage Gain (AOL)
      - Infinite Input Impedance, (ZIN)
      - Zero Output Impedance, (ZOUT)
      - Infinite Bandwidth, (BW)
      - Zero Output Offset
    - - Finite gain (as large as possible)
      - Finite input impedance (as large as possible)
      - Non-zero output impedance (as small as possible)
      - Finite bandwidth (as large as possible)
      - Offset voltage and offset currents (as small as possible)
    - - Vout = Aol(V+ -- V-)
      - If V+ > V-, VOUT = VCC (HIGH)
      - If V+ < V-, VOUT = VEE (LOW)
      - If V+ = V-, VOUT = 0V
  - - - Can operate at higher voltages/deliver higher output current.
      - Can be customized for high performance.
      - Can be repaired piecemeal.
    - - Bulky and not cost effective.
      - More connections required for a system, thus more prone to failure as compared to ICs.
  - - - Extremely small size – Thousands of times smaller than discrete circuits.
      - Very small weight owing to miniaturised circuit.
      - Very low cost because of simultaneous production of hundreds of similar circuits on a small semiconductor wafer.
      - More reliable because of elimination of soldered joints and need for fewer interconnections.
      - Lower power consumption because of their smaller size.
      - Easy replacement -more economical to replace them than to repair them.
    - - Cannot be repaired. Has to be replaced entirely.
      - Limited/Low power rating.
      - Need of connecting inductors and transformers exterior to the semiconductor chip as it is not possible to fabricate inductor and transformers on the semiconductor chip surface.
      - Operates only at fairly low voltage.
- - - - VR1 = R1/(R1 + R2) x E
- - - - NPN
        
        Vin1 and Vin2 are grounded (Vb = 0)
        
        Vbe = Vb - Ve, Ve = -0.7V
        Vbe = 0.7V, Vb = 0V
        
        Using ohm law, Ire = (Ve - Vee)/Re
        
        Assume the transistors are well matched and large Beta
        
        Ie = Ire/2
        Ic = Ie
        Ib = Ic/Beta
        
        Irc = Ic => Vrc = Irc x Rc = Ic x Rc
        
        Using KVL, Vc = Vcc - Vrc
        
        Vout1 = Vout2 = Vc
      - PNP
        
        Veb = Ve - Vb, Ve = 0.7V
        Vbe = 0.7V, Vb = 0V
        
        Using ohm law, Ire = (Vcc - Ve)/Re
        
        Using KVL, Vc = Vee + Vrc
    - - To analysis its differential mode, the transistors are redrawn in equivalent t-model, and the following equations are obtained:
      - AC emitter resistance,re = Vt/Ie = 25mV/Ie
        Differential Mode gain, Adm = Rc/2re
      - To analysis its common mode, it is obtained from “half circuits”:
      - Common Mode gain, Adm = Rc/2Re
      - The ratio of the differential gain and common mode gain is:
      - Common Mode Rejection Ratio, CMRR = Adm/Acm
    - - Function
        
        What is common in both inputs? Noise
        
        What is different in both inputs? Voice
        
        For a good amplifier:
        
        Differential mode gain should be amplified
        
        Common mode gain should be attenuated
      - CMRR(dB) = 20log|Adm/Acm|
- - - - If V+ > V-, VOUT = VCC
      - If V+ < V-, VOUT = VEE
      - If V+ = V-, VOUT = 0V
  - - - The Output (VOUT) terminal is connected to the Inverting (V-) terminal.
      - Configuration
        
        𝑽+≈𝑽−
        
        𝑽𝑫=𝑽+ − 𝑽− → 𝟎
        
        applications
        
        Inverting Amplifier
        
        𝑽𝒐𝒍𝒕𝒂𝒈𝒆 𝑮𝒂𝒊𝒏,
        𝑽𝑶𝑼𝑻/𝑽𝑰𝑵 =−𝑹𝟐/𝑹1
        
        As it name implies, it inverts all kinds of input voltage signals (alternating or constant) but amplified by a gain.
        
        Similarities
        
        Uses negative feedback configuration.
        Uses 2 resistors in its most basic form
        
        Differences
        
        VIN applied indirectly to the “-” terminal.
        The output signal is 1800 out of phase with the input signal
        
        VIN applied directly to the “+” terminal.
        The output signal is in phase with the input signal
        
        Non-inverting Amplifier
        
        𝑽𝑶𝑼𝑻/𝑽𝑰𝑵 =𝑹𝟐/𝑹𝟏 +𝟏
        
        As it name implies, it simply amplifies the input voltage signals (alternating or constant) with a gain.
        
        Voltage Buffers/ Followers
        
        𝑽𝑶𝑼𝑻/𝑽𝑰𝑵 =𝟏
        
        Due to the very high input impedance, very low output impedance of the op-amp and the unity gain of the voltage follower, the RLOAD will receive maximum voltage, and hence minimizes loading effect.
        
        Summing Amplifier
        
        Non-inverting Summing Amplifier
        
        𝑉𝑂𝑈𝑇=(1 + 𝑅𝐹/𝑅𝐼 ) [𝑅2/(𝑅1+𝑅2 ) x 𝑉𝐼𝑁1 + 𝑅1/(𝑅1+𝑅2 ) x 𝑉𝐼𝑁2]
        
        Inverting Summing Amplifier
        
        𝑉𝑂𝑈𝑇=−(𝑅𝐹/𝑅1 * 𝑉𝐼𝑁1 + 𝑅𝐹/𝑅2 x 𝑉𝐼𝑁2 + 𝑅𝐹/𝑅3 x 𝑉𝐼𝑁3 + …)
        
        Multiple Vin
    - - The Output (VOUT) terminal is connected to the Non-Inverting (V+) terminal.