THVD1450: IO Level of input signals

Hi Nachiketh,

Not without a level translator - the THVD1450 uses LVTTL/TTL input logic levels - so VIH(min) = 2V and VIL(max) = 0.8V so 1.8V I/O signals will not work - and it should be noted that the "R" pin VOH is going to be pretty close to  THVD1450 VCC level.

You can look at our THVD2450V - it won't be pin to pin but it is offered in a small 3mm x 3mm VSON package. It is an improved version of the THVD1450 in most aspects -high bus abs. max voltage (+/-70V), extended common mode range (+/-25V), optional slew rate limiting, timer based idle/short/open fail-safe which grants more hysteresis than the THVD1450's style of fail-safe, and it allows two voltage supplies - one for the logic pins (which can be from 1.65V to 5.5V) and one is for the RS-485 bus (3V to 5.5V)  - so in this part you can use 1.8V signals when the logic supply is powered with 1.8V. This device does have a lot more premium features than the THVD1450.  It is a bit more expensive and you most likely could find a level translator + THVD1450 that would be cheaper - but in terms of performance the THVD2450V is a really good device and wouldn't require the same board space that a two chip solution would and the design is a bit easier since the level translator functionality is integrated into the THVD2450V. 

Please let me know if you have any other questions!

Best,

Parker Dodson