Conduction State
Electrical resistance measured across internal semiconductor switch terminals during fully active conduction states governs signal attenuation. Test engineers measure switch ON resistance to evaluate signal insertion loss and DC voltage drop across analog multiplexers and pass switches. Typical values range from fractional ohms in power switches to tens of ohms in signal switches.
Voltage Attenuation
Signal current flowing through internal pass transistors creates a voltage drop proportional to channel resistance. High switch ON resistance degrades signal levels passing to receiving nodes, reducing noise margins on digital communication lines. High-frequency signals experience attenuation and phase delay when switch resistance combines with parasitic load capacitance.
Thermal Response
Semiconductor channel conductivity varies non-linearly with applied gate voltage and signal voltage levels. Elevated junction temperatures increase switch ON resistance due to reduced electron mobility within silicon channels. Variations in switch resistance across the operating signal voltage range induce harmonic distortion in analog measurement signals.
Passing large supply currents through high-resistance switches induces localized thermal heating, accelerating semiconductor aging and degrading long-term device reliability.
Measurement Protocol
Automated test equipment applies known constant currents across closed switch terminals to measure resulting voltage drops. Data sheets report maximum switch ON resistance across specified temperature and supply voltage ranges. Verification protocols confirm compliance before component installation into sensor interface boards.
