SCES641E May 2007 – October 2023 TXB0102
PRODUCTION DATA
TI recommends careful printed-circuit board (PCB) layout practices with short PCB trace lengths to avoid excessive capacitive loading and to assure that proper O.S. triggering takes place. PCB signal trace-lengths must be kept short enough such that the round trip delay of any reflection is less than the one-shot duration. This improves signal integrity by assuring that any reflection sees a low impedance at the driver. The O.S. circuits have been designed to stay on for approximately 10 ns. The maximum capacitance of the lumped load that is driven also depends directly on the one-shot duration. With heavy capacitive loads, the one-shot can time-out before the signal is driven fully to the positive rail. The O.S. duration has been set to best optimize trade-offs between dynamic ICC, load driving capability, and maximum bit-rate considerations. Both PCB trace length and connectors add to the capacitance that the TXB0102 output sees, so TI recommends that this lumped-load capacitance be considered to avoid O.S. retriggering, bus contention, output signal oscillations, or other adverse system-level affects.