What is maximum switching frequency can be supported with this part?
Thanks.
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Thanks. Our application needs 1.2V supply. can this device itself switch at >200Mhz with this supply?
Hi George,
The AUC family of products can detect input changes at greater than 200 MHz for a 1.2-V supply, please see this FAQ for details on why I got the below table from a related flip-flop, and the below image from the SN74AUC74 datasheet for the clock speeds that the AUC family generally supports:
It's very important that you understand what "open-drain" means for your system though - it is very unlikely that you will be able to operate at 200 MHz with an open-drain part.
The output of an open-drain device can only pull the output low. In the 'high' state, the device's output is just in the high-impedance state (it has no positive driver, like what a push-pull output would provide).
In this case, you are counting on a pull-up resistor to charge the output load. Assuming a light load of 15 pF, and the smallest reasonable pull-up resistor to use (267 Ω), we can estimate the minimum rise time for the low to high transition:
t_r ~= 2.2 * R * C = 8.8 ns
Given that the desired bit width is 2.5 ns (for 200 MHz operation), this would obviously not work.
Thank you Emrys and Clemens for the prompt feedback. It solved my question. Thanks.