TXS0108E: TXS0108E

There is no intended function. These resistors model the resistance of the bond wires, traces, and the pass transistor.

Without the low-side one-shots, falling edges (from A to B, or from B to A) are pulled low only through these R1/R2 resistors. With the low-side one-shots, falling edges are faster. (R1/R2 are not very large, so the difference is not very large.)

Hi Rachel,

The  falling edge one-shot architecture is unique to the TXS0108E allowing for higher data rate capability. It is described further in section 2.2 in A Guide to Voltage Translation With TXS-Type Translators.

Regards,

Jack

R1/R2 are not resistors. They describe the resistance of other components (bond wire, traces, MOSFET channel). It is not possible to remove them. (Other TXS devices also have them.)

Hey Rachel,

During a logic low state, the Npass turns on, essentially connecting the input to the output. The falling one shot circuitry helps to bypass the internal 40kohm pullup resistors to give the output an additional edge during a logic low state. 

Regards,

Jack