Other Parts Discussed in Thread: SN74AVC4T774, TXB0104,
Hi TI experts,
I have tested level shifter for SPI(25Mhz).
The datasheet shows the calculation formula for the pull-up resistance.
But it is not working even by applying a calculated value. Even applying the reference values does not work.
In some cases VLO is too large, and in others the input is output as it is.
So I figured out the resistors through trial and error.
<Final value>
R247, R248, R250: open
R249: 1Kohm
R251,R253,R254: 294ohm
R252: open
Below waveform show very long rising time. How can fix it. If I reduce pull-up resistance, VLO is increase.
ch1: B1(pin10)