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SN74LV164A: Application check

Part Number: SN74LV164A
Other Parts Discussed in Thread: SN74HC595

Hi Sirs,

Sorry to bother you.

Could you help double confirm our application as below?

We would like Serial to Parallel.



  • Hi Shu-Cheng,
    I can verify that you have the correct pinout of the SN74LV164A.
    The bypass capacitor is correctly sized (placement is more critical than size though).
    It's fine to directly tie pin 2 and pin 9 to VCC_3V3_CPU.

    Otherwise I have no idea if the device is being used correctly. I don't see the load, signal timing, operating voltages, supply, etc.
  • Hi Sirs,

    Thanks for your reply.

    We will use the behavior mode of the LED (Serial data to parallel data)

    In addition, can this one lock the state of the previous one? After the Trigger, change the state together.

  • I think you want the SN74HC595. That device allows changing the register values while holding the outputs constant, then you can use the RCLK pin to change all outputs at the same time.

    For most applications, this won't matter though -- the device can be changed MUCH faster than the human eye can see the LEDs.
  • Hi Sirs,

    Thanks for your reply.

    1. Does SN74LV164ADR could lock the previous state?

    2. If I want to connect 2 pieces , how do I get from the first string to the second one on data??

  • 1. Yes - as long as you don't clock data through, the output is "locked"
    If I understand correctly though, you want to clock data through while the outputs remain the same, which is why I recommended a different part that has that capability.

    2. To connect 2 devices in series, connect QH to A, tie B HIGH, connect both CLK pins together.