HD74BC573A

HD74BC573A Octal D Type Transparent Latches With 3 State Outputs ADE-205-021A (Z) Rev. 1 March 1993 Description The HD74BC573A 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 D type latches with three state outputs in a 20 pin package. When the latch enable input is high, the Q outputs will follow the D inputs. When the latch enable goes low, data at the D inputs will be retained at the outputs until latch enable returns high again. When a high logic level is applied to the output control input, all outputs go to a high impedance state, regardless of what signals are present at the other inputs and the state of the storage elements. Features Input/Output are at high impedance state when power supply is off. Built in input pull up circuit can make input pins be open, when not used. TTL level input Wide operating temperature range Ta = –40 to + 85°C Function Table Output Control L L L H H L X Z Q0 : : : : : Latch Enable H H L X Data H L X X Output Q H L Q0 Z High leve Low level Immaterial High impedance Level of Q before the indicated steady input conditions were established HD74BC573A Pin Arrangement Output Control 1D 2D 3D 4D 5D 6D 7D 8D GND 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 VCC 1Q 2Q 3Q 4Q 5Q 6Q 7Q 8Q Latch Enable (Top vie...