Download You are basically correct but unfortunately it is not always true

The best way to check for diodes is look at the absolute max spec Iik and Iok. If current limits a
(+/-) then there is a diode to Vcc and Gnd.
If there is only a (–) current then there is only a diode to Vcc.
If there is no diode to Vcc on the input then it will usually mean that it is over voltage tolerant.
If there is no diode on the output it does not usually mean it is over voltage tolerant. There is
usually a parasitic diode on the output that will not allow voltages more than .5V over Vcc, but you
can go above Vcc if it is in tri-state
On most of out little logic parts there will be a Vi and Vo spec. This is the spec the customer
should go by. It will tell the customer what is allowed.
Most of our devices will not let you pull the output above VCC. There are only a few that will.
Some switches and open drain parts.
No clamp to VCC on input or output
In absolute max spec
In absolute max spec
In recommended spec
Or
No clamp to Vcc on input
output
there is a Vcc clamp on
In absolute max spec
In recommended spec
Clamp to Vcc on both input and output
In absolute max spec
In recommended spec
If there is no diode to Vcc on the input then it will usually mean that it is over voltage tolerant.
If there is no diode on the output it does not usually mean it is over voltage tolerant. There is
usually a parasitic diode on the output that will not allow voltages more than .5V over Vcc.
On most of out little logic parts there will be a Vi and Vo spec. This will tell the customer what is
allowed.