Final answer:
The input resistances Rid and Ricm of a differential amplifier circuit can be calculated using the small-signal model, circuit analysis techniques, and other circuit component values, as well as transistor parameters like β and VA.
Step-by-step explanation:
To determine the input resistances Rid and Ricm of a differential amplifier circuit with given transistor parameters (β=100, VBE(on)=0.7 V, and VA=100 V), you need to consider both the differential and common-mode operation of the circuit. Rid, differential input resistance, is influenced by the transistor parameters and the arrangement of the circuit components, while Ricm, common-mode input resistance, is computed based on the ability of the circuit to reject common-mode signals and is typically high in well-designed differential amplifiers.
To analytically determine these resistances, use the small-signal model of the transistors, incorporating the parameters given, and apply circuit analysis techniques such as KVL (Kirchhoff's Voltage Law) and KCL (Kirchhoff's Current Law). However, the exact formula to calculate Rid and Ricm requires additional information about the circuit, such as the values of other resistors in the circuit, the configuration of the differential pair, and any current mirror or active load used. Typically, β (the current gain) and VA (the Early voltage) are used to determine the small-signal parameters of the transistors, which then influence the computation of the input resistances.