Hi, Expertes,
customer wants to use SN74LVC125A for 3:1 switch, the input frenquency is about 3Mhz. But there is no spec shows when the input is off, the input impendence of this device.it's Hiz ? or do you have the impendence ?
And the datasheet doesn't have the bandwith ? do you have the bandwith of this device ?
Thanks for your help.
Flora Wang
Flora,
Since the SN74LVC125A is a logic devie, its input impedance is always going to be high, regardless of whether the ~OE pin is high or low. The I_I spec in the datasheet will give you an idea about what the input impedance might be. This appears to be change depending on temperature, but it always has a high value.
As for the bandwidth of this device, the maximum frequency of an output square wave is going to greatly depend on the capacitance on the output. A higher capacitance will cause a slower rise time on the output, which will lower the frequency for practicle applications.
Many of the specifications in the datasheet were determined at an input frequency of 10 MHz, so 3 MHz should be well within the operating range.
Jamss
James
