The HS40xx datasheet seems to contain only very sparse electrical specifications. I was wondering if there are more detailed specifications available, especially for the SCL and SDA pins.
Are the absolute maximum (as well as recommended operating) voltages for these also 3.6 V? Or can these open drain pins be connected to a higher voltage (e.g. 5 V) IIC bus with the part powered at 3.3 V?
What are the switching voltage levels and sink currents (versus voltage drop) at the various possible supply voltages?
Hi,
Thanks for the request. We can connect maximum up to 3.6V through the SCL and SDA. For higher voltage it will not work. Could you please clarify the switching voltage not getting? Moreover, please tell me the end application and also comment on the interfacing to target MCU so that we would better understand your situation.
Regards:
Raja.
Thank you for your reply Raja. So far I have not started testing as the HS40xx electrical specifications were not clear to me. The test setup I would initially use has mixed 5V/3.3V components, with the main IIC bus having pull-up resistors to 5V.
Some 3.3V parts on the setup do have true open drain pins that can interface directly with 5V buses (often with 6-7 V abs max ratings), hence my original question.
If I am understanding you correctly the SDA and SCL lines of the HS40xx would need a level shifter in order to connect to a 5 V IIC bus. It would still be very useful to have more detailed information on switching voltage thresholds and sink currents of the HS40xx parts.
Hi Eric,
Yes, you must connect level shifter in between. The SCL and SDA characteristic of HS40XX is identical to the international standard. For voltage threshold please see the attached image.
Raja
Note: We will also add this information in next datasheet iteration.
Ok, thank you. Please also note that figure 1 of the datasheet seems to show a bottom view of the device, not a top view as stated.