[IBIS-Users] IBIS load

Hi experts,

 

According to the cookbook, when extracting V-T data, it is recommended
to use a load circuit of 1R + 1F into manufacturer's suggested pullup
resistor termination and voltage. However, when I use the suggested
pullup resistor (1.5K), the rising waveform takes up to 100ns to
stabilize, but the falling waveform requires less than 10ns. This
creates inaccuracy due to the resolution of the points (when I use 100ns
simulation time). In the IBIS model, I also included a waveform for
50Ohm pullup resistor (as recommended by cookbook). The rising waveform
for this is also within 10ns. I wonder if I can generate IBIS model with
ONLY 50 Ohm pullup because the resolution is more appropriate in this
case? I have verified this model and the simulation shows acceptable
waveforms.

 

Kindly advice whether it is a MUST to have a 1.5K pullup resistor V-T
table.

 

Thank you.

 

Best regards,

 

Mei Yee Ng

IC Design Engineer 

Illumination and Color Management

Solid-state Illumination Division

Avago Technologies Malaysia

Tel no: +604-6108515

 


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