CMOS可预置分频N计数器 CMOS PRESETTABLE DIVIDE-BY-N COUNTER
CD4018B types consist of 5 Johnson-Counter stages, buffered Q outputs from each stage, and counter preset control gating. CLOCK, RESET, DATA, PRESET ENABLE, and 5 individual JAM inputs are provided. Divide by 10, 8, 6, 4, or 2 counter configurations can be implemented by feeding the Q\5, Q\4, Q\3, Q\2, Q\1 signals, respectively, back to the DATA input. Divide-by-9, 7, 5, or 3 counter configurations can be implemented by the use of a CD4011B to gate the feedback connection to the DATA input. Divide-by functions grater than 10 can be achieved by use of multiple CD4018B units. The counter is advanced one count at the positive clock-signal transition.. Schmitt Trigger action on the clock line permits unlimited clock rise and fall times. A high RESET signal clear the counter to an all-zero condition. A high PRESET-ENABLE signal allows information on the JAM inputs to preset the counter. Anti-lock gating is provided to assure the proper counting sequence.
The CD4018B types are supplied in 16-lead hermetic dual-in-line ceramic packages F3A suffix, 16-lead dual-in-line plastic packages E suffix, 16-lead small-outline packages M, M96, MT, and NSR suffixes, and 16-lead thin shrink small-outline packages PW and PWR suffixes.