MC14521B屬于集成電路（IC）的計數(shù)器除法器。由安森美半導(dǎo)體公司制造生產(chǎn)的MC14521B計數(shù)器，除法器計數(shù)器和除法器 IC 是數(shù)字邏輯器件，可對輸入發(fā)生的邏輯轉(zhuǎn)換進行計數(shù)，然后使用多個并行輸出重新發(fā)送累加的計數(shù)，和/或生成單個輸出信號轉(zhuǎn)換，從而對應(yīng)用某些整數(shù)數(shù)量輸入信號轉(zhuǎn)換進行響應(yīng)。除了簡單的事件計數(shù)，它們還可用于各種頻率合成應(yīng)用。

24?Stage Frequency Divider

The MC14521B consists of a chain of 24 flip?flops with an input circuit that allows three modes of operation. The input will function as a crystal oscillator, an RC oscillator, oras an input buffer for an external oscillator. Each flip?flop divides the frequency of the previous flip?flop by two, consequently this part will count up to 2 24 = 16,777,216. The count advances on the negative going edge of the clock. The outputs of the last seven?stages are available for added flexibility.

Features

?All Stages are Resettable

?Reset Disables the RC Oscillator for Low Standby Power Drain

?RC and Crystal Oscillator Outputs Are Capable of Driving External Loads

?Test Mode to Reduce Test Time

?VDD′and VSS′Pins Brought Out on Crystal Oscillator Inverter to Allow the Connection of External Resistors for Low?Power Operation

?Supply Voltage Range = 3.0 Vdc to 18 Vdc

?Capable of Driving Two Low?Power TTL Loads or One Low?Power Schottky TTL Load over the Rated Temperature Range

?Pb?Free Packages are Available*