DESCRIPTION:

The QS3389 provides a set of 20 active termination circuits which pull data bus signals to the voltage rails. This feature prevents bus signals from floating in the threshold region of standard TTL I/O devices. The QS3389 can replace resistor termination solutions which add DC power dissipation and increase component count. Input clamp diodes help to reduce reflections and undershoot in transmission line environments. Importantly, the terminator circuits pull signals to whichever logic state the signal previously held (high or low). For this reason, this device is also referred to as a last value latch. This device is appropriate for data bus applications where interfacing devices have CMOS inputs with low input currents.

FEATURES:

? Active termination pulls bus pins to rails

? Holds last value of input signal

? Ideal replacement for resistive termination

? Ultra low 3μA DC quiescent current

? Bus-hold eliminates floating bus lines and reduces static power consumption

? Low power QCMOS technology

? Operates over 2.7V to 5.5V Vcc range

? TTL-compatible input and output levels

? No added noise or ground bounce

? 20 independent terminator circuits

? Available in QSOP package

APPLICATIONS:

? Bus termination

? Extend data hold time