Abstract: A bimodal portable telephone provides cellular service and improved cordless service in a common handset. Operation of the bimodal portable telephone in a cellular telephone system provides telephone service over a wide geographical area of coverage through operation with multiple cellular bases and in a cordless telephone system provides telephone service over a localized geographical area of coverage through operation with an associated cordless base. The cordless service provides improved performance over convention cordless telephone service by advantageously employing a frequency hopping spread spectrum modulation technique for communications between the portable telephone and the cordless base unit. This improved performance achieves increased operating range of the cordless telephone system.

Abstract: Two input stages (10,12) are interconnected so that their input common mode voltage ranges to one side of signal ground are combined to provide a common mode voltage range substantially equal to the supply voltage. One stage has N-channel differential input transistors (N1,N2), while the other stage has P-channel differential input transistors (P3,P4). The input current branches of the stages are interconnected by current mirror transistors (N6,N7) so that signal current is shared. The output (22) is taken from one branch of the N-type stage (10) and coupled to an output stage (24) with frequency compensation (C,R).