This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN65HVD1792: Input Impedance

Part Number: SN65HVD1792

Hi,

Good Day. What is the input impedance of each receiver input of SN65HVD1792? Thank you very much.

Best Regards,

Ray Vincent

  • Hi Ray Vincent,

    This spec is hard to define because of the non-linearity of transistor devices. Changes in voltages seen at the receiver pins changes the amount of current through those pins ultimately changing resistance. Maybe the spec you would be looking for is the leakage current coming from the receiver pins when the receiver is off. This would normally be a small current (uA) accompanied by a fairly large input resistance (kohm range). Unfortunately the datasheet doesn't provide this exact measurement.

    Instead we can look at the bus input current at varying voltage levels to the receiver: 

    For the 92 device Vi =  +12V volts, there is 125uA max current. R = 12V / 125uA = 96kohm, for Vi = -7V there is -100uA current. R = -7 / -100uA = 70kohm. 

    These are just two points on the input resistance curve. Of course the input impedance of the receiver inputs will change depending on input voltage. 

    Regards,

    Tyler