Other Parts Discussed in Thread: DAC8760,
Hi guys.
I am looking for a solution for protecting the voltage and current output of the DAC8760.
You can see the thread about DAC8760 trouble here.
The problem is that the customer does not want to apply the connector at our sensor's cable. Therefore it is possible to mistakenly connect the cable.
The cable has three terminal: positive power supply +VBATT (from 10V to 32V), GND and DAC8760 voltage¤t output.
The board is protected from power supply reverse polarity by the series diode apply on +VBATT.
Now the problem is: how can I protect the DAC output from customer miswiring in all possibile combinations?
I think is a good idea to introduce an analog switch after the DAC output (TMUX7219). I would connect 0-10V out to S1, 4-20mA out to S2 and D to the board output. So I place the TVS to the board output to protect the TMUX7219 from the ESD events.
I can supply TMUX7219 with +5V internally generated from buck converter or directly from +VBATT supply.
My question is: what happens if the customer apply, for example, +VBATT to the board output (pin D of TMUX7219) and, for example, output cable to +VBATT pin board? And in the other cases?
What happens if the TMUX7219 is not powered and, for example, a voltage is applied to the output? Is it possible the voltage pass through the analog switch and is applied to the DAC8760 output.
BR,
Gabriele.