Parallel Port Transceivers Replace Two Devices

Supporting both IEEE1284-I and -II bi-directional parallel communications between personal computers and peripherals, the 74LVC161284TTR and 74LVCZ161284ATTR parallel-port transceivers can each replace the functionality of two 74ACT1284 devices. Both devices feature a translation capability that allows outputs on the cable side to interface with a 5V signal and a pull-up resistor integrated on each open-drain output to eliminate the need for an external resistor. And their A-port pins have standard 4 mA totem-pole outputs, while the B-port pins offer the ability to source or sink up to 14 mA. Other common features include TTL-compatible inputs and a 9-ns delay. The 74LVCZ161284ATTR prevents printer system errors caused by the cable's BUSY signal being set false at power-on and includes a feature to ensure that any printers connected to it start properly when power is applied - one set of outputs stays high after power is applied until a related input also goes high. Available in TSSOPs with a commercial temperature range, prices range from $0.78 to $0.85 each/1,000. More details are available from STMICROELECTRONICS INC., Lexington, MA. (781) 861-2650.