I have a circuit where I need to multiplex 16 analog channels to a single ADC pin. I set it up with a CD4067B. It works great. I just select the channel I want using the 4 address pins, and it serves the channel on the common pin.
I have Vdd at 5V. It seems as though the chip can only handle input signals less than about Vdd+0.4V. Above that, regardless of the input voltage, output is fixed at Vdd+0.4V.
Problem is, my analog channels range from 3.3 - to 15V. Is there a multiplexer chip than can handle this switching with only a 5V rail?
Or do I have to add a 15V rail to the circuit?
This is a great forum.
I have Vdd at 5V. It seems as though the chip can only handle input signals less than about Vdd+0.4V. Above that, regardless of the input voltage, output is fixed at Vdd+0.4V.
Problem is, my analog channels range from 3.3 - to 15V. Is there a multiplexer chip than can handle this switching with only a 5V rail?
Or do I have to add a 15V rail to the circuit?
This is a great forum.