器件名称:
CD54HC4538
功能描述:
High-Speed CMOS Logic Dual Retriggerable Precision Monostable Multivibrator
文件大小:
382.19KB 共18页
简 介:
CD54HC4538, CD74HC4538, CD54HCT4538, CD74HCT4538 Data sheet acquired from Harris Semiconductor SCHS123E June 1998 - Revised October 2003 High-Speed CMOS Logic Dual Retriggerable Precision Monostable Multivibrator Description The ’HC4538 and ’HCT4538 are dual retriggerable/resettable monostable precision multivibrators for xed voltage timing applications. 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. The propagation delay from trigger input-tooutput transition and the propagation delay from reset inputto-output transition are independent of RX and CX. Leading-edge triggering (A) and trailing edge triggering (B) inputs are provided for triggering from either edge of the input pulse. An unused “A” input should be tied to GND and an unused B should be tied to VCC. On power up the IC is reset. Unused resets and sections must be terminated. In normal operation the circuit retriggers on the application of each new trigger pulse. To operate in the non-triggerable mode Q is connected to B when leading edge triggering (A) is used or Q is connected to A when trailing edge triggering (B) is used. The period (τ) can be calculated from τ = (0.7) RX, CX; RMIN is 5k. CMIN is 0pF. Features Retriggerable/Resettable Capability Trigger and Reset Propagation Delays Independent of RX, CX Triggering from the Leading or Trailing Edge ……
