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SN74CBT3125: Can this chip handle the 1.8V logic as well? Considering my VCC is 5V and OE pins are Pulled - Low.

Part Number: SN74CBT3125

Does this chip handle i/p with 1.8V logic? (Please note, VCC is 5V and OE pins are Tied to Gnd)

When 1.8V applied on any of the I/P, Same can be seen on O/P?

Will there be any drop?

Can i configure 1.8V on 2 Switches and 2 Switches with 3.3V logic ?

  • Hi Phani,

    Yes it can handle 1.8V signals at the input/output of the chip when VCC = 5V. 

    For 1.8V signals it depends on the load impedance at the output of the switch. If it is high impedance any loss over the switch will be negligible, the max switch resistance Ron is 15 Ohms for the spec'd input voltage of 2.4V. 

    For 3.3V signals, the max Ron will be greater than 15 Ohms, but the loss over the switch is negligible is you have a high impedance load. This part will pass 3.3V signals but it can't pass signals much larger than that with a VCC = 5V. 

    You can approximate the loss using Ohm's Law as such: Vout = Vin * ZL/(ZL + Ron), if ZL >> Ron;  Vin ~ Vout

    For your final question, as long as the VCC is 5V as stated, you can configure 2 channels with 3.3V signals and 2 with 1.8V signals.


    Best Regards,

    Parker Dodson