ICDICTIONARY

Short Description

BCD To Binary Converter.

General Description

This monolithic converter is derived from the 256-bit read only memories, DM5488, and DM7488. Emitter con- nections are made to provide direct read-out of converted codes at outputs Y8 through Y1, as shown in the function tables. These converters demonstrate the versatility of a read only memory in that an unlimited number of reference tables or conversion tables may be built into a system. Both of these converters comprehend that the least significant bits (LSB) of the binary and BCD codes are logically equal, and in each case the LSB bypasses the converter as illus- trated in the typical applications. This means that a 6-bit converter is produced in each case. Both devices are cas- cadable to N bits. An overriding enable input is provided on each converter which when taken high inhibits the function, causing all out- puts to go high. For this reason, and to minimize power consumption, unused outputs Y7 and Y8 of the 185A and all ``don't care'' conditions of the 184 are programmed high. The outputs are of the open-collector type.

Features

The 6-bit BCD-to-binary function of the DM74184 is analo- gous to the algorithm: 1. Shift BCD number right one bit and examine each decade. Subtract three from each 4-bit decade containing a binary value greater than seven. 2. Shift right, examine, and correct after each shift until the least significant decade contains a number smaller than eight and all other converted decades contain zeros. In addition to BCD-to-binary conversion, the DM74184 is programmed to generate BCD 9's complement or BCD 10's complement. Again, in each case, one bit of the complement code is logically equal to one of the BCD bits; therefore, these complements can be produced on three lines. As outputs Y6, Y7 and Y8 are not required in the BCD-to-binary conversion, they are utilized to provide these complement codes as specified in the function table when the devices are connected as shown.

Applications

See Datasheet

Absolute Maximum Rating

Supply Voltage >> 7V Input Voltage >> 5.5V Output Voltage >> 7V Operating Free Air Temperature Range: 0C to +70C Storage Temperature Range: -65C to +150C

Datasheet Link

http://pdf1.alldatasheet.com/datasheet-pdf/view/102202/NSC/DM74184.html