| Number of channels (#) | 8 |
| Technology Family | S |
| Supply voltage (Min) (V) | 4.75 |
| Supply voltage (Max) (V) | 5.25 |
| Input type | Bipolar |
| Output type | 3-State |
| Clock Frequency (Max) (MHz) | 75 |
| IOL (Max) (mA) | 20 |
| IOH (Max) (mA) | -6.5 |
| ICC (Max) (uA) | 40000 |
| Features | Very high speed (tpd 5-10ns) |
- Choice of Eight Latches or Eight D-Type Flip-Flops in a Single Package
- 3-State Bus-Driving Outputs
- Full Parallel Access for Loading
- Buffered Control Inputs
- Clock-Enable Input Has Hysteresis to Improve Noise Rejection (’S373 and ’S374)
- P-N-P Inputs Reduce DC Loading on Data Lines (’S373 and ’S374)
These 8-bit registers feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. The high-impedance 3-state and increased high-logic-level drive provide these registers with the capability of being connected directly to and driving the bus lines in a bus-organized system without need for interface or pullup components. These devices are particularly attractive for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.
The eight latches of the ?LS373 and ?S373 are transparent D-type latches, meaning that while the enable (C or CLK) input is high, the Q outputs follow the data (D) inputs. When C or CLK is taken low, the output is latched at the level of the data that was set up.
The eight flip-flops of the ?LS374 and ?S374 are edge-triggered D-type flip-flops. On the positive transition of the clock, the Q outputs are set to the logic states that were set up at the D inputs.
Schmitt-trigger buffered inputs at the enable/clock lines of the ?S373 and ?S374 devices simplify system design as ac and dc noise rejection is improved by typically 400 mV due to the input hysteresis. A buffered output-control (OC) input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.
OC\ does not affect the internal operation of the latches or flip-flops. That is, the old data can be retained or new data can be entered, even while the outputs are off.