74HC4538 Philips, 74HC4538 Datasheet - Page 11

• Manufacturer Part Number: 74HC4538
• Description: Dual retriggerable precision monostable multivibrator
• Manufacturer: Philips

Philips Semiconductors
September 1993
Dual retriggerable precision monostable
multivibrator
Fig.11 Power-down protection circuit.
Fig.12 Typical pulse width accuracy versus external capacitance; V
Fig.13 Typical pulse width accuracy versus external resistance; V
11
Power-down considerations
A large capacitor (C
powering-down the monostable due to the energy stored
in this capacitor. When a system containing this device is
powered-down or a rapid decrease of V
the monostable may sustain damage, due to the capacitor
discharging through the input protection diodes. To avoid
this possibility, use a damping diode (D
germanium or Schottky type diode able to withstand large
current surges and connect as shown in Fig.11.
CC
CC
X
) may cause problems when
= 4.5 V; T
= 4.5 V; T
74HC/HCT4538
amb
amb
= 25 C.
= 25 C.
Product specification
CC
X
) preferably a
to zero occurs,