2007-05-04 08:09 PM
2011-05-17 12:42 AM
Hi,
I want to use a STR912 in combination with TTL IC's. I need a bidirectional level shifter (3.3V <-> 5V) for my GPIO's. Any idea where I can find such a device. Luc Vercruysse2011-05-17 12:42 AM
....I need a bidirectional level shifter (3.3V <-> 5V) for my GPIO's.
Any idea where I can find such a device... Why? STR91x's I/O is 5V tolerant (5.5V max), from datasheet first page: 5 V tolerant, 16 have high sink current (8 mA) and section: 6.4 DC electrical characteristics. In case I am missing something, check: ti.com
2011-05-17 12:42 AM
I agree, but I need a voltage shifter from 3.3V => 5V to drive my CMOS inputs...
Luc2011-05-17 12:42 AM
I want to use a STR912 in combination with TTL IC's....
I need a voltage shifter from 3.3V => 5V to drive my CMOS inputs ...and now I am confused like a baby in a topless bar! :o
2011-05-17 12:42 AM
OK TTL is not correct.(English is not my native...)
I mean that I want to use the STR912 to access 5V devices (all technologies, 74LS, 74HCT, CMOS ...) I think CMOS is the worst case concerning input levels (input voltage seen as ''high'' is above 3.3V). For that reason I need voltage shift. Luc2011-05-17 12:42 AM
look at 74LVC4245 :)
2011-05-17 12:42 AM
maybe 74LCX244 will help you
2011-05-17 12:42 AM
Unless the system is battery powered, pullup resistors should do the job as well.
2011-05-17 12:42 AM
...worst case concerning input levels (input voltage seen as ''high'' is above 3.3V)
True. You may want to look at this: > but, it looks like you got some hints what to use already....