SN74LS593

The SN74LS593 belongs to 'LS593 family. And the 'LS592 comes in a 16-pin package and consists of a parallel input, 8-bit storage register feeding an 8-bit binary counter. Both the register and the counter have individual positive-edge-triggered clocks. In addition, the counter has direct load and clear functions. A low-going RCO pulse will be obtained when the counter reaches the hex word FF. Expansion is easily accomplished for two stages by connecting RCO of the first stage to CCKEN of the second stage. Cascading for larger count chains can be accomplished by connecting RCO of each stage to CCK of the following stage. The 'LS593 comes in a 20-pin package and has all the features of the 'LS592 plus 3-state I/O, which provides parallel counter outputs. The tables below show the operation of the enable (CCKEN, CCKEN) inputs. A register clock enable (RCKEN) is also provided.

The features of SN74LS593 can be summarized as (1)parallel register inputs (LS592); (2)parallel 3-state I/O: register inputs/counter outputs ('LS593); (3)counter has direct overriding load and clear; (4)accurate counter frequency: DC to 20 MHz.

The absolute maximum ratings of SN74LS593 are (1)supply voltage, VCC (see Note 1): 7V; (2)input voltage (excluding I/O ports): 7V; (3)Off-state output voltage (including I/O ports): 5.5V; (4)operating tree-air temperature range: 0°C to 70°C; (5)storage temperature range: - 65°C to 150°C(NOTE 1: Voltage values are with respect to the network ground terminal.).