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LMH6580: LMH6580

DRUILHE yvan
Intellectual 540 points
Part Number: LMH6580
Other Parts Discussed in Thread: TCA5405, TCA9536, LMH6720, TCA9537

Hello
I wanted to replace the DG884 8 x 4 Wideband Video Crosspoint Array muxtiplexer with the LMH6580.
I am missing a function on this product, the 4 DISABLED outputs function.

Address A3 functions as an output turn-off command. There
are four open-drain DISABLE pins that are active low when the
particular output is off. They are designed to interface directly
with the disable pin of the CLC410 current feedback op amp.

Do you have an 8x4 Analog Crosspoint with this function?

Thank you for your help.
Please find attached the DG884 datsheet see page 3 bit A3

DG884.PDF

  • 0
    Guru 317450 points

    TI does not make any such switch with separate disable outputs. You would need to use separate GPIOs, or an I/O expander like the TCA5405 or TCA9536.

  • 0 in reply to Clemens Ladisch
    TI__Mastermind 24440 points

    Hello,

    To add more context from my understanding the LM6580  has serial controlled device input and outputs,  while the D884 has directly accessible   select pins that control the configuration of the switches. Both of these devices can be controlled to disable any input from the output but the D884 has additional pins to send a disable signal to the CLC410 device letting it know that which ever  output it was connected to is disabled which can also disable the op amp.

    Looking into the mux portfolio i wasn't able to find a device the added D884 feature.

    First to help me better understand is using this the LM6580 which is serially controlled switch configurations acceptable for your application?

    If yes we can try to work with another product line like Clemens  suggested to find you a competitive solution 

  • 0 in reply to Kameron Hill
    Intellectual 540 points

    Hello,

    We need the 8X4 matrix of the multiplexer.
    Serial mode for programming the multiplexer is not a problem. The only function missing from this multiplexer is the 4 open drain disable Outputs that allow direct interfacing to the CLC410 disable pin. In our case, we'll be driving the LMH6720's SD pin.

  • 0 in reply to DRUILHE yvan
    TI__Mastermind 24440 points

    Hello,

    Thanks for the extra info.

    So I think the best idea is to look into Clemens solution for this application. So I will send this thread to the  correct product line to see if an io expander can help get the disable function.

    Regards,

    Kameron

  • 0 in reply to DRUILHE yvan
    TI__Mastermind 48588 points

    Hi DRUILHE,

    Yes an IO expander would allow for your system to have additional GPIO ports available. Our IO expanders such as the TCA9536 and TCA9537 are able to supply an additional 4 GPIOs to use, and are configured and controlled via the I2C bus. These GPIOs can be used as open-drain outputs as well. 

    Set the device to the input configuration in order to disable the pull-down FET and set the device in HIGH-Z. When you want to pull low, set the output port register to LOW, and then change the configuration register from input to output mode. 

    Regards,

    Tyler