Hi,
As you can see in my attachment, the SN75468 COM pin is tied to VCC (12VDC) and E is tied to GND1.
The outputs of the SN75468 are connected to a relay, also seen in the attachment.
The inputs on the SN75468 receive a signal from an STM32F427ZGT6 uC. The uC is powered from 3V3 and GND1.
I am using an output pin on the STM32F to drive the input on the SN75468. I'm not clear if this will work or not since I never used this circuit in the past.
I did go through the SN754X datasheet and read the Electrical Characteristics (also attached) and Vi(on) has a max input of 3 volts (@ IC = 300mA). This is where I get confused is about the current, Ic.
My questions are:
1. Is there any unforeseen issues, that is not apparent, that I should not connect my uC output to the SN75468?
2. The uC's I/O's are CMOS and TTL compliant. Likewise, the SN75468 is CMOS and TTL compliant. Will the SN75X require a lot of current from the STM32F?
3. Will the STM32F even work if connected to the SN75468?
Thanks,SN75468.docx
Brian