Mazi3
Advanced Member level 4
hi,
we have problems with analog multiplexer (dg406), becouse of crosstalk between chanels. at the imput, there are lf358 operation amplifiers, but they are disturbed with "parasitic switch" inside multiplexer which one short circuit input to negative voltage at channel change.
we solve some this using 1k resistor in series with opamp output. but this system is designed for 16bit data acquisition, which has 90+dB dynamic range. the multiplexer has only 70 dB crosstalk isolation. this is 16 channels system.
is there any better multiplexer? any layout guidelines? or is it better to use ADC with internal mux? becouse to have ADC on every chanel it become too costly
Regards!
we have problems with analog multiplexer (dg406), becouse of crosstalk between chanels. at the imput, there are lf358 operation amplifiers, but they are disturbed with "parasitic switch" inside multiplexer which one short circuit input to negative voltage at channel change.
we solve some this using 1k resistor in series with opamp output. but this system is designed for 16bit data acquisition, which has 90+dB dynamic range. the multiplexer has only 70 dB crosstalk isolation. this is 16 channels system.
is there any better multiplexer? any layout guidelines? or is it better to use ADC with internal mux? becouse to have ADC on every chanel it become too costly
Regards!