器件名称:
CD54HC221F3A
功能描述:
High-Speed CMOS Logic Dual Monostable Multivibrator with Reset
文件大小:
379.6KB 共18页
简 介:
CD54HC221, CD74HC221, CD74HCT221 Data sheet acquired from Harris Semiconductor SCHS166F November 1997 - Revised October 2003 High-Speed CMOS Logic Dual Monostable Multivibrator with Reset Description The ’HC221 and CD74HCT221 are dual monostable multivibrators with reset. An external resistor (RX) and an external capacitor (CX) control the timing and the accuracy for the circuit. Adjustment of RX and CX provides a wide range of output pulse widths from the Q and Q terminals. Pulse triggering on the B input occurs at a particular voltage level and is not related to the rise and fall time of the trigger pulse. Once triggered, the outputs are independent of further trigger inputs on A and B. The output pulse can be terminated by a LOW level on the Reset (R) pin. Trailing Edge triggering (A) and leading-edge-triggering (B) inputs are provided for triggering from either edge of the input pulse. On power up, the IC is reset. If either Mono is not used each input (on the unused device) must be terminated either high or low. The minimum value of external resistance, RX, is typically 500. The minimum value of external capacitance, CX, is 0pF. The calculation for the pulse width is tW = 0.7 RXCX at VCC = 4.5V. Features Overriding RESET Terminates Output Pulse [ /Title (CD74 HC221 , CD74 HCT22 1) /Subject (High Speed CMOS Logic Dual Monos table Multi- Triggering from the Leading or Trailing Edge Q and Q Buffered Outputs Separate Resets Wide Range of Output-Pulse Widths Schmit……
