The Intermediate StageThe intermediate stage is composed of Q16, Q17and Q13B.Common-collector configuration for Q16 gives thisstage a high input resistance as well as reducesthe load effect on the input stage.Common-emitter configuration for Q1z provideshigh voltage gain because of the active load Q13BCapacitor Cc introduces the miller compensationto insure that the op amp has a very high unit-gain frequency.Microelectronic Circuits
Microelectronic Circuits The Intermediate Stage ⚫ The intermediate stage is composed of Q16, Q17 and Q13B. ⚫ Common-collector configuration for Q16 gives this stage a high input resistance as well as reduces the load effect on the input stage. ⚫ Common-emitter configuration for Q17 provides high voltage gain because of the active load Q13B. ⚫ Capacitor Cc introduces the miller compensation to insure that the op amp has a very high unitgain frequency
Vee(+15V)13/Q13BQ1sR=01270OutQ18R, =5Ro=27040knRs=C0239k030JnCc=30pFOOIREF1023Q16Qro>R, =Q>R =R=>50k0V5k1000OR,=R250kn=>R,=2Z1knQ221knMRi=150knVEEC-15V
Microelectronic Circuits
The Output StageThe output stage is the efficient circuit called class ABoutput stage.Voltage source composed of Q18 and Q1g supplies theDC voltage for Q14 and Q2o in order to reduce thecross-overdistortion.Q23 is the CC configuration to reduce the load effect onintermediate stage.Short-circuit protection circuitry> Forward protection is implemented by R and Q15-> Reverse protection is implemented by Rz, Q21,current source(Q24, Q22) and intermediate stage.Microelectronic Circuits
Microelectronic Circuits The Output Stage ⚫ The output stage is the efficient circuit called class AB output stage. ⚫ Voltage source composed of Q18 and Q19 supplies the DC voltage for Q14 and Q20 in order to reduce the cross-over distortion. ⚫ Q23 is the CC configuration to reduce the load effect on intermediate stage. ⚫ Short-circuit protection circuitry ➢ Forward protection is implemented by R6 and Q15. ➢ Reverse protection is implemented by R7 , Q21, current source(Q24, Q22) and intermediate stage
TheOutput StageVccVccOU10RVEE-VEE(b(a)(a) The emitter follower is a class A output stage. (b) Class B output stageMicroelectronicCircuits
Microelectronic Circuits The Output Stage (a) The emitter follower is a class A output stage. (b) Class B output stage
The Output Stage>Wave of a class B output stage fed withan input sinusoid.>Positive and negative cycles are unableto connect perfectly due to the turn-onTimevoltage of the transistors> This wave form has the nonlineardistortion called crossover distortion> To reduce the crossover distortion canbe implemented by supplying the constant(c)DC voltage at the base terminals.Microelectronic Circuits
Microelectronic Circuits The Output Stage ➢Wave of a class B output stage fed with an input sinusoid. ➢Positive and negative cycles are unable to connect perfectly due to the turn-on voltage of the transistors. ➢This wave form has the nonlinear distortion called crossover distortion. ➢To reduce the crossover distortion can be implemented by supplying the constant DC voltage at the base terminals