DUAL DECADE COUNTER; DUAL 4-STAGE BINARY COUNTER
The SN54 / 74LS390 and SN54 / 74LS393 each contain a pair of high-speed...
DUAL DECADE COUNTER; DUAL 4-STAGE BINARY COUNTER
The SN54 / 74LS390 and SN54 / 74LS393 each contain a pair of high-speed 4-stage ripple counters. Each half of the LS390 is partitioned into a divide-by-two section and a divide-by five section, with a separate clock input for each section. The two sections can be connected to count in the 8.4.2.1 BCD code or they can count in a biquinary sequence to provide a square wave (50% duty cycle) at the final output. Each half of the LS393 operates as a Modulo-16 binary divider, with the last three stages triggered in a ripple fashion. In both the LS390 and the LS393, the flip-flops are triggered by a HIGH-to-LOW transition of their CP inputs. Each half of each circuit type has a Master Reset input which responds to a HIGH signal by forcing all four outputs to the LOW state.
SN54/74LS390 SN54/74LS393
DUAL DECADE COUNTER; DUAL 4-STAGE BINARY COUNTER
LOW POWER
SCHOTTKY
Dual Versions of LS290 and LS293 LS390 has Separate Clocks Allowing ÷ 2, ÷ 2.5, ÷ 5 Individual Asynchronous Clear for Each Counter Typical Max Count Frequency of 50 MHz Input Clamp Diodes Minimize High Speed Termination Effects
J SUFFIX CERAMIC CASE 620-09
16 1
16 1
N SUFFIX PLASTIC CASE 648-08
CONNECTION DIAGRAM DIP (TOP VIEW) SN54 / 74LS390
VCC 16 CP0 15 MR 14 Q0 13 CP1 12 Q1 11 Q2 10 Q3 9
16 1
D SUFFIX SOIC CASE 751B-03
J SUFFIX CERAMIC CASE 632-08
14 1
1 CP0
2 MR
3 Q0
4 CP1
5 Q1
6 Q2
7 Q3
8 GND
NOTE: The Flatpak version has the same pinouts (...