Other Parts Discussed in Thread: TCA9554A
We use the subject PCF8574A I/O expander in the SOIC-16 package (DW suffix).
Since they're hard to find, is there a newer more common alternate?
The TCA9554A seems likely, but what is the difference?
In Application Report SLVA787 on Selecting I2C Expanders for New Designs, the PCF prefix isn't even listed in Figure 3 decision tree -- what does that mean?
What about the NXP version of PCF8574A? Seems equivalent, tho addresses need pull-up & P-port I/Os are only weakly pulled up.
Thanks in advance for help!
Paul
