Monostable/Astable Multivibrator CD4047

Description

The CD4047B is capable of operating in either the monostable or astable mode. It requires an external capacitor (between pins 1 and 3) and an external resistor (between pins 2 and 3) to determine the output pulse width in the monostable mode, and the output frequency in the astable mode. Astable operation is enabled by a high level on the astable input or low level on the astable input. The output frequency (at 50% duty cycle) at Q and Q outputs is determined by the timing components. A frequency twice that of Q is available at the Oscillator Output; a 50% duty cycle is not guaranteed. Monostable operation is obtained when the device is triggered by LOW-to-HIGH transition at + trigger input or HIGH-to-LOW transition at – trigger input. The device can be retriggered by applying a simultaneous LOW-to-HIGH transition to both the + trigger and retrigger inputs. A high level on Reset input resets the outputs Q to LOW, Q to HIGH.

Features

•  Wide supply voltage range: 3.0V to 15V
• High noise immunity: 0.45 VDD (typ.)
•  Low power TTL compatibility: Fan out of 2 driving 74L
  or 1 driving 74LS

• Applications
  • Frequency discriminators
  • Timing circuits
  • Time-delay applications
  • Envelope detection
  • Frequency multiplication
  • Frequency division