These devices contain two independent positive-edge-triggered
D-type flip-flops. A low level at the preset () or clear () inputs sets or resets the outputs
regardless of the levels of the other inputs. When and are inactive (high), data at the
data (D) input meeting the setup-time requirements are transferred to
the outputs on the positive-going edge of the clock (CLK) pulse.
Clock triggering occurs at a voltage level and is not directly
related to the rise time of CLK. Following the hold-time interval,
data at the D input can be changed without affecting the levels at
the outputs.
The SN54ALS74A and SN54AS74A are characterized for operation over
the full military temperature range of -55°C to 125°C. The
SN74ALS74A and SN74AS74A are characterized for operation from
0°C to 70°C.
