74191 Binary counter (0 to 15)

74LS191 The SN74LS191 is a 4-bit synchronous up/down counter with up/down mode control. It has a complexity of 58 equivalent doors. The synchronous operation is provided by causing all the flip-flops to be synchronized simultaneously so that the outputs change coincident with each other when indicated by the direction logic. This mode of operation eliminates the output count spikes normally associated with asynchronous counters. The outputs of the four master-slave flip-flops are activated at a low to high transition of the clock input if the enable input is low. A stop at the Enable input inhibits the count. Level changes at the enable input should only be made when the clock input is high. The count address is determined by the level of the down/up input. When it is low, the counter counts up and when it is high, it counts down. A false clock may occur if the down/up input changes while the clock is low.

Account 8-4-2-1 BCD or Binary

Simple down/up count control line

Enable count control input

Ripple Clock Output to Cascade Connect

Asynchronously preset with load control

parallel exits

Cascading for n-bit applications

Specs

• Family: LS
• Counter Type: Binary, Up/Down
• Clock frequency: 25 MHz
• Account: 8-4-2-1 Binary
• Maximum account: 15
• Minimum supply voltage: 4.75 V
• Maximum supply voltage: 5.25 V
• Minimum operating temperature: 0 °
• Maximum operating temperature: 70 ° C
• Encapsulated: Dip
• 16 pins
• Substitute
• NTE74LS191 NTE74191