HD74BC623A

HD74BC623A Octal Bus Transceivers With 3 State Outputs ADE-205-025 (Z) Rev.0 June 1993 Description The HD74BC623A provides high drivability and operation equal to or better than high speed bipolar standard logic IC by using Bi-CMOS process. The device features low power dissipation that is about 1/5 of high speed bipolar logic IC. When the frequency is 10 MHz. The device has eight bus transceivers with three state outputs in a 20 pin package. 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. Features Input/Output are at high impedance state when power supply is off. Input pins can be open, when not used, owing to built in input pull up circuit. Input is TTL level. Wide operating temperature range Ta = –40 to +85°C. Function Table Enable Inputs GBA L H H L GAB L H L H Operation B data to A bus A data to B bus Isolation B data to A bus A data to B bus H : L : High level Low level HD74BC623A Pin Arrangement GAB A1 A2 A3 A4 A5 A6 A7 A8 GND 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 VCC GBA B1 B2 B3 B4 B5 B6 B7 B8 (Top view) Absolute Maximum Ratings Item Supply voltage Input diode current Input voltage Output voltage Off state output voltage Storage temperature Note: Symbol VCC I IK VIN VOUT VOUT(off) Tstg Rating –0.5 to +7.0 ±30 –0.5 to +7.5 –0.5 t...