SN74TVC16222A replacement for temperature issue

Hi Bill, if the functionality of the TVC family was good for your application, the LSF should be fine as well. It has a very similar structure to the TVC device. What are the restrictions that you are mentioning?

Hi Ryan,

The datasheet for the LSF states that if either IO is push-pull, then the channel must be limited to a unidirectional channel with direction control. There was no constraint like this in the TVC datasheet, of which I am aware.

The application is mixed digital and analog where some outputs drive transistor circuits and some inputs are driven by transistor circuits and others by +5v HCMOS devices. It's a very old design and we are designing in a modern FPGA albeit using LVCMOS +3.3V IO. We had to use diode clamps on some of the transistor inputs to insure that the maximum voltage of the TVC was not exceeded. Will we need to do this for the LSF as well?

We also have a requirement to be operational at +95°C for 30 minutes, but about 20 minutes into the soak we start to have IO failures and we believe the TVC channels are becoming more resistive (RDSon increasing well beyond the 10 Ohms maximum) causing excessive voltage drops and thus signal failures.

The reason we decided to design in the TVC was that the legacy product has had very good results using commercial 0-70°C parts and is still able to operate continuously from -55°C to +71, and at +95°C for the required 30 minutes. I had hoped that the TVC would have had some margin with respect to the +95°C temperature since it is an industrial rated part.

Thank you for the quick reply,

--Bill