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Multiplexer suggestion for digital signals

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girishji:
I am trying to connect 2n (2 banks of n each) inputs to n GPIO pins of an mcu. I want 2 inputs routed to 1 GPIO pin through a 2:1 mux.  Mcu could be any 3v3 ones like rp2040 or st32xx. For digital signals what mux to use? It needs to be low power and fast switching. Say under a microsecond switching time.
There are IO expanders but they use I2C and slow.

rstofer:
Quad 2-Input MUX for 3.3-5V

https://assets.nexperia.com/documents/data-sheet/74AHC_AHCT257.pdf

girishji:
Thank you, this has what I was looking for.

paulca:
A 74H595 shift register is what I have used previously.  I "believe" they are bidirectional.  There are 16 bit ones and maybe 32bit ones as well.

The basic idea is you put your individual digital states into a number with each taking a bit value like 1, 2, 4, 8....  Expressions like CH1 & CH2 & CH3.

Then you "shift" that out the GPIO port as a series of Hi/Low pulsing a clock GPIO each one.  When you are ready, you hit the pin to transfer what was on the shift register into the output register.    Granted that's 3 GPIOs for 8/16/24/32.  Current is limited too depending on which shift register you use you can be limited to 7mA per pin and likely the same as the MCU and 40mA over all.  Higher power output multiplexers do exist of course.

The below is a jelly bean, cheap and easy chip.

https://www.ti.com/product/SN74HC595

You mention fast switching... the 74H series might be good up to 3Mhz something like that.  So it won't do stuff like I2S or I2C at any practically rate.

Terry Bites:
You dont need muxes if you use tristate logic.

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