Would something like this work?http://www.mouser.com/ds/2/302/RB751_SER-104980.pdfThe board will be surface mount. The divider has a 23k5 R so current is limited.
If I change VREF do I need to protect against V > VREF
or is the threshold still V > Vcc?
If I use a 10K current limiting resistor before the diodes would that affect the accuracy?