Other Parts Discussed in Thread: TCAN1043
Tool/software:
hi,
I use TCAN1043ADMTRQ1 in my design , I want the CAN trasciver to go to Sleeo Mode as soon as possible, but not throgh the Normal Mode.
I power up Vsup(cold power on start up), VCC and and VIO are Powered normal , the TCAN1043 is in standby mode beacause both EN and nSTB are pull-down by 47K resistor .
then the MCU control its IO pin to this command " EN = HIGH fistly and then nSTB =HIGH " to force the CAN IC to go to Normal mode .
I see the nFAULT becomes to High level after nSTB becomes high , but the delay time is about 600mS.
when I control the CAN to sleep mode by command "nSTB =Low, keep EN=high" ,the CAN IC is in sleep mode , I can observe the nFAULT becomes to high-impendance .
when I re-control nSTB=high, I mean the CAN transciver transition from Sleep mode to normal mode , the nFAULT is only 4uS delay after the nSTB rising edge.
my question is :
why nFAULT is delay too much time to nSTB rising edge when the cold power on?