HD74HC620 Datasheet | Hitachi Semiconductor

Description This octal bus transceiver is designed for asynchronous two-way munication between data buses. The control fuction implementation allows for maximum flexibility in timing. This device allows data transmission from the A bus to the B bus or from the B bus to the A bus depending upon the logic levels at the enable inputs (GBA and GAB). The enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives these devices the capability to store data by simultaneous enabling of GBA and GAB. Each output reinforces its input in this transceiver configuration. Thus, when both control inputs are enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (16 in all) will remain at their last states. The 8-bit codes appearing on the two sets of buses will be identical for the HD74HC623 or coplementary for the HD74HC620. Features - - - - - High Speed Operation: tpd (Bus to Bus) = 12 ns typ (CL = 50 p F) High Output Current: Fanout of 15 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) Function Table Enable Inputs GBA L H H L GAB L H L H Operation HD74HC620 B data to A bus A data to B bus Isolation B data to A bus, A data to B bus HD74HC623 B data to A bus A data to B bus Isolation B data to A bus, A data to B bus HD74HC620/HD74HC623 Pin Arrangement Enable GAB 1 A1 2 A2 3 A3 4 A4 5 A5 6 A6 7 A7 8 A8 9 GND 10 (Top view) 20 VCC 19 Enable GBA 18 B1 17 B2 16 B3 15 B4 14 B5 13 B6 12 B7 11 B8 Absolute Maximum Ratings Item Supply voltage range Input voltage Output voltage Output current DC current drain per VCC GND DC input diode current DC output diode current Power Dissipation per package Storage temperature Symbol VCC VIN VOUT I OUT I CC, I GND I IK I OK PT Tstg Rating - 0.5 to +7.0 - 0.5 to VCC + 0.5 - 0.5 to VCC + 0.5 ±35 ±75 ±20 ±20 500 - 65 to +150 Unit V V V m...