General 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.

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

Special Features

■ Low power consumption: special CMOS oscillator configuration

■ Monostable (one-shot) or astable (free-running) operation

■ True and complemented buffered outputs

■ Only one external R and C required

Monostable Multivibrator Features

■ Positive- or negative-edge trigger

■ Output pulse width independent of trigger pulse duration

■ Retriggerable option for pulse width expansion

■ Long pulse widths possible using small RC components by means of external counter provision

■ Fast recovery time essentially independent of pulse width

■ Pulse-width accuracy maintained at duty cycles approaching 100

Astable Multivibrator Features

■ Free-running or gatable operating modes

■ 50 duty cycle

■ Oscillator output available

■ Good astable frequency stability

typical= ±2 + 0.03/°C @ 100 kHz

frequency= ±0.5 + 0.015/°C @ 10 kHz

deviation (circuits trimmed to frequency VDD = 10V ±10)

Applications

• Frequency discriminators

• Timing circuits

• Time-delay applications

• Envelope detection

• Frequency multiplication

• Frequency division