74LS90
DESCRIPTION
- The ’90 is a 4-stage ripple counter containing a high speed flip-flop acting as a divide-by-two and three flip-flops connected as a divideby-five counter. It can be connected to operate with a conventional BCD out put pattern or it can be connected to provide a 50% duty cycle output. In the BCD mode, HIGH signals on the Master Set (MS) inputs set the outputs to BCD nine. HIGH signals on the Master Reset (MR) inputs force all outputs LOW. For a similar counter with corner power pins, see the ’LS290; for dual versions, see the ’LS390 and ’LS490.
ORDERING CODE: See Section 9
PKGS
PIN OUT
MERCIAL GRADE
Vcc = +5.0 V ±5%, T a = 0°C to +70°C
MILITARY GRADE
Vcc = +5.0 V ±10%, TA = -55° C to +125° C
Plastic DIP (P)
A 7490APC, 74LS90PC
Ceramic DIP (D)
A 7490ADC, 74LS90DC 5490ADM, 54LS90DM
Flatpak (F)
A 7490AFC, 74LS90FC
5490AFM, 54LS90FM
PKG TYPE
9A 6A 3I
LOGIC SYMBOL 67
Vcc = Pin 5 GND = Pin 10 NC = Pins 4,13
INPUT LOADING/FAN-OUT: See Section 3 for U.L....
