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Differential and MultistageAmplifiers
Outline
•The MOS Differential Pair•Small-Signal Operation of the MOS Differential Pair•The BJT Differential Pair•Other Nonideal Characteristics of the Differential
Amplifier•The Differential Amplifier with Active Load•Frequency Response of the Differential Amplifier•Multistage Amplifiers
Differential-to-Single-Ended
A Simple but inefficient approach Active-Loaded
Active-Loaded Differential Pair
Circuit at equilibrium Differential input applied
Short-Circuit Transconductance Gm
Differential Gain = Short-circuit transconductance Gm Output resistance Ro
Output Resistance Ro
Differential Gain = Short-circuit transconductance Gm Output resistance Ro
Ad =
Common-Mode Gain and CMRR
BJT Differential Pair with Active Load
Gm =Rid =
Ro and Ad
Ro = Ad =
Common-Mode Gain and CMRR
Systematic Input Offset Voltage
VOS =
Higher Voltage Gain with Active Load
Ad =
Outline
•The MOS Differential Pair•Small-Signal Operation of the MOS Differential Pair•The BJT Differential Pair•Other Nonideal Characteristics of the Differential
Amplifier•The Differential Amplifier with Active Load•Frequency Response of the Differential Amplifier•Multistage Amplifiers
Resistively Loaded MOS Amplifier
Differential Half-Circuit
Acm and fZ
Common-mode Half-circuit
CM Gain, Diff Gain, and CMRR
