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PCA9306: Low level

Yuta Nishie
Genius 5005 points
Part Number: PCA9306

Tool/software:

Hi,

I have some questions.

1. Please tell me the input signal voltage range to recognize Low.

2. Also, please tell me the voltage range when the output signal is Low.

3. A pull-up resistor of 10 kΩ is connected to SDA and SCL. SDA becomes 0 V as a Low signal, but SCL becomes about 165 mV. Is this correct operation? VREF is 3.3V.

Best Regards,

Nishie

  • 0
    Guru 317060 points

    This devices does not have buffered inputs or outputs; there are no switching thresholds.

    • For voltages below VREF1, the device works as an analog switch. The output voltage is the input voltage plus the voltage drop over the switch. The switch behaves like a small resistor, so the voltage drop depends on the current through the switch, which depends on the pull-up resistor on the other side.
    • For voltages above VREF1, the switch is open, and the output voltage is determined by the pull-up resistor.
  • 0 in reply to Clemens Ladisch
    Genius 5005 points

    Hi, 

    Thank you for your support.

    If you have graphs of output current and on-resistance, I would appreciate it if you could send them to me.

    Best Regards,

    Nishie

  • +1 in reply to Yuta Nishie
    Guru 317060 points

    There is nothing but the RON specification.

    (I²C uses currents not above 3 mA, so the voltage drop over the LSF should be negligible.)

  • +1 in reply to Clemens Ladisch
    TI__Mastermind 47888 points

    Hi Yuta,

    The typical characteristic graphs are found in section 6.10 of the datasheet. 

    We have graphs representing on-resistance (Ron) vs. input voltage (VSDA1 or VSCL1). 

    We don't have graphs for output current vs. on-resistance. 

    Regards,

    Tyler