SN74BCT2414,pdf(Memory Decoder

The SN74BCT2414 is a decoder specially designed to be used in memory systems with battery backup during power failure. The two independent 2-line to 4-line decoders with separate and common control inputs may be externally cascaded to implement a 3-line to 8-line decoder.

The circuit has two supply voltage inputs: the voltage monitor (bandgap) is powered via the V_CC terminal; the internal logic of the circuit is powered via the V_bat terminal. In case V_CC drops below 3.65 V (nominal), the voltage monitor forces the voltage-control (VS) and decoder outputs (Y) to the high level. VS may be used to disconnect the supply voltage of the memories (V_bat) from the system supply. This output is switched off when the on-chip supply voltage monitor detects a power failure.