HD74LS273

The HD74LS273 is designed as octal D-type positice edge triggered flip-flop with clear which utilize LSTTL circuitry to implement D-type flip-flop logic with a direct clear input. Imformation at the D inputs meeting the setup time requirements is transferred to the Q outputs on the positive-going edge of the clock pulse. Clock triggering occurs at a particular voltage level and is not directly related to the transition time of the positive going pulse. When the clock input is at either the high or low level, the D input signal has no effect at the output.

Some recommended operating conditions of HD74LS273 have been concluded into several points as follow. (1)Its supply voltage would be min 4.75V and typ 5.00V and max 5.25V. (2)Its output current high level would be max -400uA. (3)Its output current low level would be max 8mA. (4)Its clock frequency would be min 0MHz and max 30MHz. (5)Its clock and clear pulse width would be min 20ns. (6)Its setup time would be min 20ns for data and would be min 25ns for clear inactive-state. (7)Its data hold time would be min 5ns. It should be noted that the arrow indicates the rising edge of clock pulse.

Also some electrical characteristics of HD74LS273 are concluded as follow. (1)Its input voltage would be min 2.0V for high level and would be max 0.8V for low level. (2)Its output voltage would be min 2.7V for high level and would be max 0.5V for low level. (3)Its input current would be max 20uA for high level and would be max -0.4mA for low level. (4)Its short-circuit output current would be min -20mA and max -100mA. (5)Its supply current would be typ 17mA and max 27mA. (6)Its input clamp voltage would be max -1.5V with test conditions of Vcc=4.75V and Iin=-18mA. (7)Its maximum clock frequency would be min 30MHz with test conditions of CL=15pF and RL=2kohms. (8)Its propagation delay time with inputs clear would be typ 18ns and max 27ns. (9)Its propagation delay time with inputs of clock would be typ 17ns and max 27ns. And so on. If you have any question or suggestion or want to know more information of HD74LS273,  please contact us for details. Thank you!