SN54LS90 - 4-BIT BINARY COUNTER
The LS90, LS92, and LS93 are 4-bit ripple type Decade, Divide-By-Twelve, and Binary Counters respectively.
Each device consists of four master/slave flip-flops which are internally connected to provide a divide-by-two section and a divide-by-five (LS90), divide-by-six (LS92), or divide-by-eight (LS9
DECADE COUNTER; DIVIDE-BY-TWELVE COUNTER; 4-BIT BINARY COUNTER The SN54 / 74LS90, SN54 / 74LS92 and SN54 / 74LS93 are high-speed 4-bit ripple type counters partitioned into two sections.
Each counter has a divide-by-two section and either a divide-by-five (LS90), divide-by-six (LS92) or divide-by-eight (LS93) section which are triggered by a HIGH-to-LOW transition on the clock inputs.
Each section can be used separately or tied together (Q to CP) to form BCD, bi-quinary, modulo-12, or modulo-16
SN54LS90 Features
* 2 48 34 50 46 70 46 70 ns 10 16 14 21 10 16 14 21 10 16 14 21 ns tPLH tPHL tPLH tPHL tPLH tPHL tPHL CP1 Input to Q2 Output CP1 Input to Q3 Output MS Input to Q0 and Q3 Outputs MS Input to Q1 a
