Philips Semiconductors
Product specification
Programmable delay timer with oscillator
74HC/HCT5555
• retriggerable/non-retriggerable
FEATURES
GENERAL DESCRIPTION
monostable
• Positive and negative edge
triggered
The 74HC/HCT5555 are high-speed
Si-gate CMOS devices and are pin
compatible with low power Schottky
TTL (LSTTL). They are specified in
compliance with JEDEC standard
no. 7A.
• automatic power-ON reset
• output control logic
• Retriggerable or non-retriggerable
• Programmable delay
• oscillator control logic
• overriding asynchronous master
reset (MR).
minimum: 100 ns
maximum: depends on input
frequency and division ratio
• Divide-by range of 2 to 224
The 74HC/HCT5555 are precision
programmable delay timers which
consist of:
• Direct reset terminates output
• 24-stage binary counter
pulse
• integrated oscillator (using external
• Very low power consumption in
timing components)
triggered start mode
• 3 oscillator operating modes:
– RC oscillator
QUICK REFERENCE DATA
GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns.
– Crystal oscillator
SYMBOL
PHL/tPLH
PARAMETER
CONDITIONS
TYP.
UNIT
– External oscillator
t
propagation delay
A, B to Q/Q
CL = 15 pF;
VCC = 5 V
• Device is unaffected by variations
in temperature and VCC when using
an external oscillator
24
19
26
24
ns
MR to Q/Q
20
28
ns
ns
• Automatic power-ON reset
RS to Q/Q
• Schmitt trigger action on both
trigger inputs
CI
input capacitance
3.5 3.5 pF
23 36 pF
CPD
power dissipation
capacitance per buffer
notes 1 and 2
• Direct drive for a power transistor
• Low power consumption in active
mode with respect to TTL type
timers
Notes
1. CPD is used to determine the dynamic power dissipation (PD in µW):
PD = CPD x VCC2 x fi + Σ(CL x VCC2 x fo) where:
fi = input frequency in MHz
• High precision due to digital timing
• Output capability: 20 mA
• ICC category: MSI.
fo = output frequency in MHz
Σ(CL x VCC2 x fo) = sum of outputs.
CL = output load capacitance in pF
APPLICATIONS
VCC = supply voltage in V
• Motor control
2. For HC the condition is VI = GND to VCC
• Attic fan timers
For HCT the condition is VI = GND to VCC − 1.5 V.
• Delay circuits
• Automotive applications
• Precision timing
• Domestic appliances.
ORDERING INFORMATION
PACKAGE
EXTENDED TYPE
NUMBER
PINS PIN POSITION MATERIAL
CODE
74HC/HCT5555N
74HC/HCT5555D
16
16
DIL
plastic
plastic
SOT38Z
SO16
SOT109A
September 1993
2