资 源 简 介
The CS5525/CS5526 A/D converter is optimizedfor the measurement of thermocouples. It is designedwith a single analog input, but includes fourdigital output pins to control analog switches andmultiplexers. The performance characteristics ofan analog switch or multiplexer in a thermocoupledigitizer application are important because of thetypical protection circuitry which is included in thesignal path. Figure 1 illustrates a multiplexed thermocouplecircuit which includes input protection.Resistor R, capacitor C, and diodes D1 and D2 provideinput protection for the analog switch and theA/D converter. Input protection guards againstESD (Electro-Static Discharge), high voltageglitches which can get coupled into long thermocoupleleads in an industrial environment, and incorrectconnections which can cause +24 volts tobecome directly connected to the digitizer inputterminals.
