1.6 Op-Amp Basics Basic Op-Amp Practical (Ri = high , Ro = small) Op-amp equivalent circuit Practical (Ri = high , Ro = small) Ideal (Ri =∞ , Ro = 0)

1.6 Op-Amp Basics Basic Operation of Op-Amp input voltage at minus (-) output voltage opposite in phase input voltage at plus (+) output voltage in phase Basic Op-Amp - Constant-gain multiplier Input signal is applied through resistor Ri to the minus input Output is connected to the same minus input through resistor Rf Resulting output: opposite in phase to input signal Inverting constant gain multiplier

1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier Op-amp ac equivalent circuit

1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier Redrawn equivalent circuit (for circuit analysis) Ideal Op-amp equivalent circuit

1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier Using Superposition theorem i) V1 only (set –AvVi =0) ii) –AvVi only (set V1 =0)

1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier It is shown that the ratio i/o depends only on the value of Rf and R1

1.6 Op-Amp Basics Basic Op-Amp - Unity Gain If Rf = R1 Gain with negative sign shows that the output voltage has undergone 180º phase inversion from input signal Basic Op-Amp - Constant Gain If Rf = 10R1 If we select precise values for Rf and Ri, we can obtain a wide range of gains Gain accuracy depends on resistors used Gain is slightly affected by temperature & other circuit factors

1.7 Practical Op Amp Circuits Inverting Amplifier Non-inverting Amplifier Inverting constant gain multiplier Non-inverting constant gain multiplier

1.7 Practical Op Amp Circuits Non-inverting Amplifier Non-inverting constant-gain multiplier Equivalent circuit Since Vi = 0, using voltage divider rule, Which results in;

1.8 Data Sheet LM741

1.8 Data Sheet LM741 ABSOLUTE MAXIMUM RATINGS Supply voltage = +22V Internal power dissipation = 500mW Differential input voltage = + 30V Input voltage = + 15V ELECTRICAL CHARACTERISTICS Input offset voltage Input offset current Input bias current Input resistance

1.8 Data Sheet LM741 ELECTRICAL CHARACTERISTICS Large signal voltage gain Output voltage swing Output short circuit current Supply voltage rejection ratio Bandwidth Slew rate Supply current Power consumption

1.8 Data Sheet LM741

1.8 Data Sheet LM741

1.8 Data Sheet LM741