hcf4047 STMicroelectronics, hcf4047 Datasheet - Page 7

• Manufacturer Part Number: hcf4047
• Description: Low Power Monostable/astable Multivibrator
• Manufacturer: STMicroelectronics

coupling "Q" to an external "N" counter and
resetting the counter with the trigger pulse. The
counter output pulse is fed back to the ASTABLE
input and has a duration equal to N times the
period of the multivibrator. A high level on the
EXTERNAL RESET input assures no output pulse
during an "ON" power condition. This input can
also be activated to terminate the output pulse at
any time. In the monostable mode, a high-level or
ASTABLE MODE WAVEFORMS
Typ : V
Min : V
Max : V
thus if t
variation will be (+ 5.0%, -0.0%)
In addition to variations from unit-to-unit, the
astable period may vary as a function of frequency
with respect to V
MONOSTABLE WAVEFORMS
TR
TR
TR
A
= 0.5 V
= 0.33 V
= 0.67 V
= 4.40 RC is used, the maximum
DD
DD
DD
DD
and temperature.
t
A
t
A
t
A
= 4.40 RC
= 4.62 RC
= 4.62 RC
t
t
t
1
2
3
= -RC In —————
= -RC In —————
= 2(t
power-on reset pulse, must be applied to the
EXTERNAL RESET whenever V
2 - ASTABLE MODE
The
variations from unit-to-unit as a function of
transfer-voltage (VTR) shift (33% - 67% V
free-running (astable) operation.
3 - MONOSTABLE MODE
The
variations from unit-to-unit as a function of
transfer-voltage (V
one-shot (monostable) operation.
t
t
t
1
2
M
= -RC In ———
= -RC In —————
= (t
1
+t
following analysis presents
following analysis presents
1
2
+t
)= -2RC In ———————————
2
V
2V
)= -RC In —————————
V
DD
DD
DD
2V
V
2V
V
V
TR
+ V
DD
- V
TR
DD
- V
DD
- V
TR
TR
- V
TR
(V
TR
(2V
(V
TR
DD
) shift (33% - 67% V
TR
(V
TR
DD
+ V
TR
)(V
- V
)(V
TR
DD
TR
)(2V
DD
)(2V
- V
DD
- V
DD
TR
is applied.
DD
TR
HCF4047B
)
- V
)
worst-case
worst-case
)
TR
DD
DD
)
) for
) for
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