© 2002 Fairchild Semiconductor Corporation

DS005969

www.fairchildsemi.com

October 1987

Revised March 2002

CD4047BC

Low Power Monostable/Astable Multivibrator

General Description

The CD4047B is capable of operating in either the

monostable or astable mode. It requires an external capac-

itor (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 fre-

quency (at 50% duty cycle) at Q and Q outputs is deter-

mined 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 trig-

gered 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

s Wide supply voltage range:

3.0V to 15V

s Low power TTL compatibility: Fan out of 2 driving 74L

or 1 driving 74LS

Special Features

s Low power consumption: special CMOS oscillator

configuration

s Monostable (one-shot) or astable (free-running)

operation

s True and complemented buffered outputs

s Only one external R and C required

Monostable Multivibrator

Features

s Positive- or negative-edge trigger

s Output pulse width independent of trigger pulse duration

s Retriggerable option for pulse width expansion

s Long pulse widths possible using small RC components

by means of external counter provision

s Fast recovery time essentially independent of pulse

width

s Pulse-width

accuracy

maintained

at

duty

cycles

approaching 100%

Astable Multivibrator Features

s Free-running or gatable operating modes

s 50% duty cycle

s Oscillator output available

s Good astable frequency stability

typical

= ±2% + 0.03%/°C @ 100 kHz

frequency

= ±0.5% + 0.015%/°C @ 10 kHz

±10%)

Applications

• Frequency discriminators

• Timing circuits

• Time-delay applications

• Envelope detection

• Frequency multiplication

• Frequency division

Ordering Code:

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Order Number

Package Number

Package Description

CD4047BCM

M14A

14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow

CD4047BCN

N14A

14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide