In ADV7281a datasheet, it is stated "The digital inputs of the ADV7281A are designed to work with 1.8 V signals (3.3 V for DVDDIO) and are not tolerant of 5 V signals. "
I could not clearly get the point, does that mean when 3.3V applies to VDDIO, i can still feed 1.8V digital signals, e.g. SCL and SDA pins, to ADV7281A?
But in the electronic spec, Input High Voltage is 2V minimum, it means if a 1.8V added to digital input pins, the part won't treat it as a high level.
it seems there are some conflicts here, could you kindly help to correct my understanding?
Have you referred OPTIMAL POWER-UP SEQUENCE in Page16 in ADV7281 datasheet ?
Note: Its optimal power-up sequence for the ADV7282/ADV7282-M 3.3 V DVDDIO supply, followed by the 1.8V suppliesAnd also digital inputs of the ADV7282/ADV7282-M are designed to work with 1.8V signals (3.3V for DVDDIO) and also,this is not tolerant for 5 V signals. Extra components are required if 5V logic signals must be applied to the decoder.
Appreciate your fast response.
My question is that customer is using MCU with 1.8V IOs, can they directly connect with ADV7282A-M, or level shifters must be used to bring MCU 1.8V signals to 3.3V?
The statement "digital inputs of the ADV7282/ADV7282-M are designed to work with 1.8V signals (3.3V for DVDDIO)" makes customer to believe no level shifters are needed.
But the electrical spec table said VIH is 2V minimal, 1.8V voltage will not be treated as HIGH by ADV7282A-M, this let customer think level shifters are must.
So customer thinks the statement is conflict with the electrical specification table.