ISO1643: ISO1643

Masami Akazawa

Intellectual 565 points

Part Number: ISO1643
Other Parts Discussed in Thread: INA236,

Hi Team,

I have troble INA236 with a isorator which VOL=0.6 to 0.8.

I am planning to use ISO1643 with INA236. Is this Okey?:

[Vcc is 5V] Host<-->(SIDE1)ISO1643(SIDE2)<-->INA236 [Vcc and VS are 5V]

Host: VIL=0.3*Vcc(1.5V),VOL(actual value)=0.1V

ISO1643 (SIDE1): VIL=0.48V, VOL=0.57 to 0.71V

ISO1643 (SIDE2): VIL=0.3*Vcc(1.5V), VOL=0.4V

INA236: VIL=0.4V, VOL=0.3V

Best regards,

Masami

8 months ago

0 Varun Kumar 8 months ago

TI__Genius 16540 points

Hi Masami,

Thanks for reaching out.

I don't understand your exact concern here. Can you please be specific in your problem statement?

If it is with respect to logic compatibility, then no matter which device you use - VILT(min) of receiving device should always be higher than the VOL(max) of transmitter, as per the datasheet numbers.

If the above criteria do not match as per the datasheets of Host, ISO1643 and INA236, then a reliable communication cannot be guaranteed.

Regards
Varun

0 Masami Akazawa 8 months ago in reply to Varun Kumar

Intellectual 565 points

Hi Varun,

Thank you for your reply.

I am currently designing a circuit to isolate the INA236 from host.

When I used an ISO with the specifications below (Side 1 facing the INA236 device), I was unable to communicate with the INA236 device.

ADM3260 Datasheet

Communication was also not possible when I used ISO1643 with side1 facing the INA236 device.

I think this is due to a mismatch in DC characteristics (VOL and VIL).

If side 2 of the ISO1643 is INA236 side, will the mismatch in DC characteristics be resolved? I am planning to use them in two applications, with Vcc = 3.3V and 5V. (I think AC characteristics also need to be considered, but I would like to be resolved DC characteristics issue at first)

■ INA236

INA236 Datasheet