Other Parts Discussed in Thread: SN74HCT245
Tool/software:
We are using a buffer between TLC59283 and we a receiving an extra bit on the output pin between the two TLC59283.
I created a couple of illustrations below to show the issue we are seeing.
At each step, we push out an extra bit and then latch
E.g
Push 1 bit, latch
Push 01 bit, latch
Push 001 bit, latch
Push 0001 bit, latch
This is what a normal expected behaviour is, shown in 8 steps (each shift registers only has 4 bits in our example)
This is what we see when we place a 74HCT245PW in between the TLC59283 shift registers. There is an extra bit shifted out. At step 5, when latched, there is a bit seen on both registers
At step 5 above, we pushed; 0001 latch
At step 6, we push 00001, latch But because of the extra bit at step 5, the bit has move one extra step. The happens every step afterwards. If we chain more TLC59283 with a buffer in between, keeps adding an extra bit between every shift register.
We have narrowed this down to the clock pin. If we remove the clock form the buffer and connect directly between the TLC59283 , the problem goes away.
We can also recreate this issue if we manually adjust the pins by hand ( to rule out any speed problems with MCU)
We would like to use a buffer as we want to chain up to +30 shift registers
Can anyone give any advise?
thanks in advance!
