SN74LS398D

QUAD 2-PORT REGISTER The SN54 / 74LS398 and SN54 / 74LS399 are Quad 2-Port Registers. They are the logical equivalent of a quad 2-input multiplexer followed by a quad 4-bit edge-triggered register. A Common Select input selects between two 4-bit input ports (data sources). The selected data is transferred to the output register on the LOW-to-HIGH transition of the Clock input. The SN54/ 74LS398 features both Q and Q inputs, while the SN54/ 74LS399 has only Q outputs. SN54/74LS398 SN54/74LS399 QUAD 2-PORT REGISTER LOW POWER SCHOTTKY Select From Two Data Sources Fully Positive Edge-Triggered Operation Both True and Complemented Outputs on SN54/ 74LS398 Input Clamp Diodes Limit High-Speed Termination Effects CONNECTION DIAGRAM DIP (TOP VIEW) VCC Qd 20 19 Qd 18 Iod 17 I1d 16 I1c 15 I0c 14 Qc 13 Qc 12 CP 11 16 J SUFFIX CERAMIC CASE 620-09 1 SN54 / 74LS398 N SUFFIX PLASTIC CASE 648-08 1 1 S 2 Qa 3 Qa 4 I0a 5 I1a 6 I1b 7 I0b 8 Qb 9 Qb 10 GND 16 VCC = PIN 20 GND = PIN 10 VCC 16 Qd 15 I0d 14 I1d 13 I1c 12 I0c 11 Qc 10 CP 9 16 1 D SUFFIX SOIC CASE 751B-03 SN54 / 74LS399 20 J SUFFIX CERAMIC CASE 732-03 1 1 S 2 Qa 3 I0a 4 5 6 I0b 7 Qb 8 GND I1a I1b VCC = PIN 16 GND = PIN 8 PIN NAMES LOADING (Note a) HIGH LOW 0.25 U.L. 0.25 U.L. 0.25 U.L. 0.25 U.L. 5 (2.5) U.L. 5 (2.5) U.L. 20 1 N SUFFIX PLASTIC CASE 738-03 S CP I0a – I0d I1a – I0d Qa – Qd Qa – Qd Common Select Input Clock (Active HIGH Going Edge) Input Data Inputs From Source 0 Data Inputs Fro...