The following content is an automatically extracted verbatim text
from the original manufacturer datasheet and is provided for reference purposes only.
View original datasheet text
SN54/74LS490 DUAL DECADE COUNTER
The SN54 / 74LS490 contains a pair of high-speed 4-stage ripple counters. Each half of the SN54 / 74LS490 has individual Clock, Master Reset and Master Set (Preset 9) inputs. Each section counts in the 8, 4, 2, 1 BCD code.
• • • •
Dual Version of SN54 / 74LS490 Individual Asynchronous Clear and Preset to 9 for Each Counter Count Frequency — Typically 65 MHz Input Clamp Diodes Limit High-Speed Termination Effects
DUAL DECADE COUNTER
LOW POWER SCHOTTKY
CONNECTION DIAGRAM DIP (TOP VIEW)
VCC 16 CPb 15 MRb 14 Q0b 13 MSb 12 Q1b 11 Q2b 10 Q3b 9
16 1
J SUFFIX CERAMIC CASE 620-09
1 CPa
2 MRa
3 Q0a
4 MSa
5 Q1a
6 Q2a
7 Q3a
8 GND
16 1
N SUFFIX PLASTIC CASE 648-08
PIN NAMES
LOADING (Note a) HIGH LOW 0.25 U.L. 0.25 U.L. 1.5 U.L. 5 (2.5) U.L.
SN54LS490 Datasheet
