4-173 fast and ls ttl data parallel d register with enable the mc54/74f378 is a 6-bit register with a buf fered common enable. this device is similar to the f174 but with common enable rather than common master reset. the f378 consists of six edge-triggered d-type flip-flops with individual d inputs and q outputs. the clock (cp) and enable (e ) inputs are common to all flip-flops. when the e input is low , new data is entered into the register on the low - to-high transition of the cp input. when the e input is high the register will retain the present data independent of the cp input. this circuit is designed to prevent false clocking by transitions on the e input.. ? 6-bit high-speed parallel register ? positive edge-triggered d-type inputs ? fully buffered common clock and enable inputs ? input clamp diodes limit high-speed termination effects connection diagram (top view) 15 16 14 13 12 11 10 2 1 3 4 5 6 7 v cc 9 8 q 5 d 5 d 4 q 4 d 3 q 3 cp e q 0 d 0 d 1 q 1 d 2 q 2 gnd function table inputs output e cp d n q n h x no change l h h l l l h = high voltage level l = low voltage level x = don't care z = high impedance mc54/74f378 parallel d register with enable fast ? schottky ttl j suffix ceramic case 620-09 n suffix plastic case 648-08 16 1 16 1 ordering information mc54fxxxj ceramic mc74fxxxn plastic mc74fxxxd soic 16 1 d suffix soic case 751b-03 logic symbol v cc = pin 16 gnd = pin 8 14 13 12 11 10 9 7 6 5 4 3 2 15 d 5 d 3 d 2 d 1 d 0 d 4 q 5 q 3 q 2 q 1 q 0 q 4 cp 1 e
4-174 fast and ls ttl data mc54/74f378 d 5 q 5 cp d e q d 4 q 4 cp d e q d 3 q 3 cp d e q d 2 q 2 cp d e q d 1 q 1 cp d e q logic diagram d 0 q 0 cp e cp d e q guaranteed operating ranges symbol parameter min typ max unit v cc supply voltage 54, 74 4.5 5.0 5.5 v t a operating ambient temperature range 54 55 25 125 c 74 0 25 70 i oh output current e high 54, 74 1.0 ma i ol output current e low 54, 74 20 ma dc characteristics over operating temperature range (unless otherwise specified) limits symbol parameter min typ max unit test conditions v ih input high voltage 2.0 v guaranteed input high voltage v il input low voltage 0.8 v guaranteed input low voltage v ik input clamp diode voltage 1.2 v v cc = min, i in = 18 ma v oh output high voltage 54, 74 2.5 v i ol = 1.0 ma v cc = 4.50 v 74 2.7 v i ol = 1.0 ma v cc = 4.75 v v ol output low voltage 0.5 v i ol = 20 ma v cc = min i ih input high current 20 m a v cc = max, v in = 2.7 v 0.1 ma v cc = max, v in = 7.0 v i il input low current 0.6 ma v cc = max, v in = 0.5 v i os output short circuit current (note 2) 60 150 ma v cc = max, v out = 0 v i cc power supply current 30 45 ma v cc = max, v cp = 0 v notes: 1. for conditions shown as min or max, use the appropriate value specified under recommended operating conditions for the applicable device type. 2. not more than one output should be shorted at a time, nor for more than 1 second.
4-175 fast and ls ttl data mc54/74f378 ac characteristics 54/74f 54f 74f t a = +25 c t a = 55 c to +125 c t a = 0 c to +70 c v cc = 5.0 v v cc = 5.0 v 10% v cc = 5.0 v 10% c l = 50 pf c l = 50 pf c l = 50 pf symbol parameter min typ max min max min max unit f max maximum input frequency 80 140 80 80 mhz t plh propagation delay 3.0 5.5 7.5 3.0 9.5 3.0 8.5 ns t phl cp to q n 3.5 6.0 8.5 3.5 10.5 3.5 9.5 ac operating requirements 54/74f 54f 74f t a = +25 c t a = 55 c to +125 c t a = 0 c to +70 c v cc = 5.0 v v cc = 5.0 v 10% v cc = 5.0 v 10% symbol parameter min typ max min max min max unit t s (h) setup time, high or low 4.0 4.0 4.0 t s (l) d n to cp 4.0 4.0 4.0 ns t h (h) hold time, high or low 0 0 0 t h (l) d n to cp 0 0 0 t s (h) setup time, high or low 6.0 6.0 6.0 ns t s (l) e to cp 6.0 6.0 6.0 ns t h (h) hold time, high or low 2.0 2.0 2.0 ns t h (l) e to cp 2.0 2.0 2.0 t w (h) cp pulse width, 4.0 4.0 4.0 ns t w (l) high or low 6.0 6.0 6.0
|
