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LMX2594: lmx2594

p ditore
Prodigy 20 points
Part Number: LMX2594

is muxout guaranteesd to be low if the chip select is off and the device is programmed in readback mode?

This would allow the outputs of multiple lmx2594s to be ored togetger for readback on a single line.

  • 0
    TI__Guru** 108360 points
    Hi p ditore,

    Which chip select pin you are referring to? CSB (pin 24) or CE (pin 1)?
  • 0 in reply to Noel Fung
    Prodigy 20 points

    CSB ;

    Figure 2 in the data sheet shows MUXOUT  operation when CSB is low, but I could not find if MUXOUT is low when CSB is high and the device is programmed in the Readback mode.

  • 0 in reply to p ditore
    TI__Guru** 108360 points
    Hi p ditore,

    When CSB is HIGH, SPI activity is ignored. So the SDI and SCK signals can be shared with multiple devices but the CSB must be independent to each other.
    If MUXout of Chip#1 is set to readback, then MUXout is an output pin. It is normally LOW unless a "1" is being read back.
    If you simply connect the MUXout of multiple chips together, the MUXout of the active chip will be pull-low by the idle chips. As such, you should mux multiple MUXouts with diodes.