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TS5MP645: Non active ch state

Part Number: TS5MP645

Hello Support team,

Q1. When we change SEL "L" to "H", are there any timing limitation between SEL and OE?
Q2. What state should we make non active MIPI ch? LP11 or HiZ?
Q3. Is it necessary to set active ch to the state of LP11 or HiZ before selecting other ch?
After changing active ch, do we have to set the active line the state of LP11 at first and then start image signals?

Best Regards,
Hirokazu Takahashi

  • Hi Hirokazu,

    1.  tSWITCH is the time it takes for the switch to respond after the SEL pin is changed from L to H or vice versa when the enable pin OE is supplied with a logic low

    2. The non-active MIPI channel state is controlled by the VIH and VIL levels and not by LP11 

    3. Based on which channel you are using, you will set it to high and the other non-active channels to low 

    In case you have any un-used pins, connect them to ground with a 50ohm resistor to match that transmission line impedance and reduce reflections back into the device.

    Thanks

    Saminah

  • Hello Saminah

    Thanks for your reply.

    1. tSWITCH is the time it takes for the switch to respond after the SEL pin is changed from L to H or vice versa when the enable pin OE is supplied with a logic low
    -> So, It is acceptable to set OE active during switching ch, isn't it?
    -> Are there any timing restriction from changing "OE" state "L" to changing "SEL" state?

    2. The non-active MIPI channel state is controlled by the VIH and VIL levels and not by LP11
    -> Let me know the proper state at non-active channel. "H" or "L"?

    Best Regards,
    Hirokazu Takahashi

  • Hi Hirokazu,

    1. Yes. Keep /OE at "L"  to activate the switch when you are switching the channels through "SEL".

    The "switch turn-on" time is the time it takes from OE active state to selecting the channel - The datasheet doesn't specify it but it is pretty short in the order of ns.

    2. When /OE is "L", If you are selecting the A path, SEL should be "L", and for B path, SEL should be "H". You can look at the functional table to see if a "L" or "H" on the SEL pin will deactivate the channel.

    Thanks

    Saminah

  • Hello Saminah

    Thanks for your Support.

    2. When /OE is "L", If you are selecting the A path, SEL should be "L", and for B path, SEL should be "H". You can look at the functional table to see if a "L" or "H" on the SEL pin will deactivate the channel.

    -> My question is about what proper state for non-active ch.
    If SEL="H" and B path is active, what state should we make A path? "L" or "H" or Don't care?

    Best Regards,
    Hirokazu Takahashi

  • Hi Hirokazu,

    > My question is about what proper state for non-active ch.
    If SEL="H" and B path is active, what state should we make A path? "L" or "H" or Don't care?

    When SEL="H" and B path is active, A path is already in-active because of the logic on "SEL" pin (based on the function table above) - You do not need to make A path L, H or don't care.

    Thanks

    Saminah

  • Hello Saminah

    Thanks for your Support.
    Let me confrim again.
    We don't need to set non-active mipi channel path "L" or "H". We can make non-active ch "Hi-Z".
    Is my understand correct?

    Best Regards,
    Hirokazu Takahashi

  • Hi Hirokazu

    We don't need to set non-active mipi channel path "L" or "H". We can make non-active ch "Hi-Z".

    Yes, that is correct.

    Regards

    Saminah

  • Hello Saminah

    Thanks for your reply.

    I want to confirm the ch status which we should set before non-active.
    Is it necessary to set active ch to the state of LP11 or HiZ before selecting other ch as like the attached file?

    Data status at selection.xlsx
    Please modify proper singal status on the file and post the file on your feedback in this thread.

    Best Regards,
    Hirokazu Takahashi

  • Hi Hirokazu ,

    Are you referring to the active channel of the switch or the driver? 

    The TS5MP645 is a passive FET switch and doesn't have any driver's or intelligence.  It will simply pass the signal from one side of the switch to the other.

    By default the switch will power up enabled and with the A path selected until driven externally by the processor.

    Is your application similar to below use case:

    Thanks

    Saminah

  • Hello Saminah

    Thanks for your reply.
    Yes, our application is similar with Figure 24.
    Since MIPI is bi-directional line, we want to know what state each MIPI data lines should be set at the selection change timing.

    Best Regards,
    Hirokazu Takahashi

  • Hi Hirokazu

    I would suggest to have the MIPI data lines state set to HIGH or LOW  at the selection change timing.than keeping them floating .

    Any unused data lane should be tied to Ground and not left floating as well.

    Thanks

    Saminah

  • Hello Saminah

    Thanks for your reply.
    MIPI CSI line has 2 mode, LP (Low Power) mode and HP (High Speed) mode.
    Since the state of Mipi is generally changed LP by LP11 after terminating HS transmit , I think we should set active line to LP by LP11 before changing ch.
    Mipi line state is in LP before starting HS transmit, so I think the active line should start LP11 after making active.

    This process has already posted at my previous thread.
    I attached it again below.

    3566.Data status at selection.xlsx
    Is my understand correct? If you have any application at system level application note with actual mipi state, please share it with me.
    Or since TS5MP645 is a simple analog sw product, don't TI define for the Mipi signal condition?

    Best Regards,
    Hirokazu Takahashi

  • Hi Hirokazu,

    Yes, the excel looks good - if you set active line to LP by LP11 before changing ch, you should be ok.

    I found this e2e post that might be helpful.

    Thanks

    Saminah