Patent ID: 7482853

Claim:
A MOSFET-based switching circuit for controllably coupling analog signals and digital signals through a common terminal comprising: an analog signal switching circuit coupled between an analog signal input terminal and said common terminal, and containing only a single analog signal switching MOSFET, which has its source-drain path coupled between said analog signal input terminal and said common terminal, said analog signal switching circuit including a biasing circuit coupled to said analog signal switching MOSFET, said biasing circuit being operative to cause said analog signal switching MOSFET to have a substantially constant gate-to-source voltage; and a MOS-based, or CMOS-based, digital signal switching circuit formed of one of a single MOSFET having its source-drain path coupled between a digital signal input/output terminal and said common terminal, or a pair of complementary polarity MOSFETs having their source-drain paths coupled in parallel between a digital signal input/output terminal and said common terminal.