DM74LS503

Supply Voltage . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . 7V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .  . . . . . . . . . . . . . . . . . .. . . 7V
Operating Free Air Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . .  -65°C to +150°C

Note 1: The "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The "Recommended Operating Conditions" table will define the conditions for actual device operation.

The DM74LS503 register has an active LOW Enable (E) input that is used in cascading two or more packages for longer word lengths. A HIGH signal on E, after a START operation, forces Q7 HIGH and prevents the device from accepting serial data. With the E input of an DM74LS503 connected to the CC output of a preceding (more significant) device, the DM74LS503 will be inhibited until the preceding device is filled, causing its CC output to go LOW. This LOW signal then enables the DM74LS503 to accept the serial data on subsequent clocks.