? 2000 fairchild semiconductor corporation ds009831 www.fairchildsemi.com october 1988 revised march 2000 dm74ls377 octal d-type flip-flop with common enable and clock dm74ls377 octal d-type flip-flop with common enable and clock general description the dm74ls377 is an 8-bit register built using advanced low power schottky technology. this register consists of eight d-type flip-flops with a buffered common clock and a buffered common input enable. the device is packaged in the space-saving (0.3 inch row spacing) 20-pin package. features n 8-bit high speed parallel registers n positive edge-triggered d-type flip-flops n fully buffered common clock and enable inputs ordering code: devices also available in tape and reel. specify by appending the suffix letter x to the ordering code. logic symbol v cc = pin 20 gnd = pin 10 pin descriptions connection diagram truth table h = high voltage level l = low voltage level x = immaterial order number package number package description dm74ls377wm m20b 20-lead small outline integrated circuit (soic), jedec ms-013, 0.300 wide dm74ls377n n20a 20-lead plastic dual-in-line package (pdip), jedec ms-001, 0.300 wide pin names description e enable input (active low) d0Cd7 data inputs cp clock pulse input (active rising edge) q0Cq7 flip-flop outputs inputs output e cp d n q n h x x no change l hh l ll
www.fairchildsemi.com 2 dm74ls377 functional description the dm74ls377 consists of eight edge-triggered d flip-flops with individual d inputs and q outputs. the clock (cp) and enable input (e ) are common to all flip-flops. when e is low, new data is entered into the register on the next low-to-high transition of cp. when e is high, the reg- ister will retain the present data independent of the cp. logic diagram
3 www.fairchildsemi.com dm74ls377 absolute maximum ratings (note 1) note 1: the absolute maximum ratings are those values beyond which the safety of the device cannot be guaranteed. the device should not be operated at these limits. the parametric values defined in the electrical characteristics tables are not guaranteed at the absolute maximum ratings. the recommended operating conditions table will define the conditions for actual device operation. recommended operating conditions electrical characteristics over recommended operating free air temperature range (unless otherwise noted) note 2: all typicals are at v cc = 5v, t a = 25 c. note 3: not more than one output should be shorted at a time, and the duration should not exceed one second. switching characteristics v cc = + 5.0v, t a = + 25 c supply voltage 7v input voltage 7v operating free air temperature range 0 c to + 70 c storage temperature range - 65 c to + 150 c symbol parameter min nom max units v cc supply voltage 4.75 5 5.25 v v ih high level input voltage 2 v v il low level input voltage 0.8 v i oh high level output current - 0.4 ma i ol low level output current 8 ma t a free air operating temperature 0 70 c t s (h) setup time high or low 10 ns t s (l) d n to cp 10 t h (h) hold time high or low 5.0 ns t h (l) d n to cp 5.0 t s (h) setup time high or low 10 ns t s (l) e to cp 20 t h (h) hold time high or low 5.0 ns t h (l) e to cp 5.0 t w (h) cp pulse width high or low 20 ns t w (l) 20 symbol parameter conditions min typ max units (note 2) v i input clamp voltage v cc = min, i i = - 18 ma - 1.5 v v oh high level v cc = min, i oh = max 2.7 3.4 v output voltage v il = max v ol low level v cc = min, i ol = max 0.35 0.5 output voltage v ih = min v i ol = 4 ma, v cc = min 0.25 0.4 i i input current @ max v cc = max, v i = 7v 0.1 ma input voltage v i = 10v i ih high level input current v cc = max, v i = 2.7v 20.0 m a i il low level input current v cc = max, v i = 0.4v - 0.4 ma i os short circuit output current v cc = max (note 3) - 20 - 100 ma i cc supply current v cc = max 28 ma symbol parameter r l = 2 k w , c l = 15 pf units min max f max maximum clock frequency 30 mhz t plh propagation delay 25 ns t phl cp to q n 25
www.fairchildsemi.com 4 dm74ls377 physical dimensions inches (millimeters) unless otherwise noted 20-lead small outline integrated circuit (soic), jedec ms-013, 0.300 wide package number m20b
5 www.fairchildsemi.com dm74ls377 octal d-type flip-flop with common enable and clock physical dimensions inches (millimeters) unless otherwise noted (continued) 20-lead plastic dual-in-line package (pdip), jedec ms-001, 0.300 wide package number n20a fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and fairchild reserves the right at any time without notice to change said circuitry and specifications. life support policy fairchilds products are not authorized for use as critical components in life support devices or systems without the express written approval of the president of fairchild semiconductor corporation. as used herein: 1. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be rea- sonably expected to result in a significant injury to the user. 2. a critical component in any component of a life support device or system whose failure to perform can be rea- sonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com
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