SN74LVC374A: Input and output resistance at the pins

Joe DiBartolomeo

Intellectual 2785 points

Part Number: SN74LVC374A

Hi All,

My customer would like to know the input and output resistance of the SN74LVC374ARGYR pins,

Thanks,

Regards,

Joe

over 3 years ago

0 Chad Crosby over 3 years ago

TI__Expert 6680 points

Hi Joe,

Please have your customer see the IBIS model for the part. The IBIS will have all of the information they need.

Thanks!

Chad Crosby

0 Joe DiBartolomeo over 3 years ago in reply to Chad Crosby

TI__Intellectual 2785 points

Hi Chad,

Sorry, I misunderstood the customersrequest. They wanted the input/output resistance and capacitance of the circuit (not the pins). I could not find this in the IBIS model.

I did find Ci & Co in the datasheet, page 6. But not the Ri/Ro.

Thanks,

Regards,

Joe

0 Clemens Ladisch over 3 years ago

Guru 243080 points

CMOS inputs have a very high impedance. If you want to compute the worst-case value, you can derive it from the leakage current specification: [FAQ] What is the impedance of the device's pin?

The output impedance can be derived from the voltage/current values in the IBIS model, but when you stay inside the recommended operating conditions, you can simply use the V_OL/I_OL/V_OH/I_OH values from the datasheet. At 3.3 V, it's typically 12 Ω, and 23 Ω in the worst case.

Logic

Logic forum

SN74LVC374A: Input and output resistance at the pins