TK74H373 – 250ºC 3-State Octal D-Type Transparent Latches

General Description

The Tekmos TK74H373 is a high temperature version of the 3-State Octal D-Type Transparent Latch that functions logically like these earlier versions of the 74LS373.

The TK74H373 has eight transparent D-type latches. Like other transparent latches, when the enable input (G) is high, the outputs (Q) follow the inputs (D). When the enable is low, the outputs will remain (be latched) to the level at the Q output just prior to being latched.

The eight 3-state outputs in the TK74H373 are specifically designed for driving highly capacitive or relatively low impedance loads. The relatively high output drive capability in the “Logic-1” state, as well as the high impedance state, make these devices a good choice for driving bus lines in a bus-organized system without the need for other interface components, such as pull-up resistors. The TK74H373 is particularly useful in implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The buffered output control input can put the outputs in their high impedance state or in their normal logic (High or Low) state as determined by the latch. When in the high impedance state, the outputs do not drive the busses or load them significantly.

The output control buffer does not affect the internal latch that drives it. Whatever data that would have been latched if the output were not tri-stated is present when the output is taken out of the tri-state mode.