1 General description

The 74HC5555 is a precision programmable delay timer which consist of:

? 24-stage binary counter

? integrated oscillator (using external timing components)

? retriggerable/non-retriggerable monostable

? automatic power-ON reset

? output control logic

? oscillator control logic

? overriding asynchronous master reset (MR).

The 74HC5555 inputs include clamp diodes. This enables the use of current limiting

resistors to interface inputs to voltages in excess of VCC.

2 Features and benefits

? Supply voltage range from 2.0 V to 6.0 V

? CMOS input levels

? Positive and negative edge triggered

? Retriggerable or non-retriggerable

? Programmable delay:

– minimum: 100 ns

– maximum: depends on input frequency and division ratio

? Divide-by range of 2 to 224

? Direct reset terminates output pulse

? Very low power consumption in triggered start mode

? 3 oscillator operating modes:

– RC oscillator

– Crystal oscillator

– External oscillator

? Device is unaffected by variations in temperature and VCC when using an external

oscillator

? Automatic power-ON reset

? Schmitt trigger action on both trigger inputs

? Direct drive for a power transistor

? High precision due to digital timing

? Complies with JEDEC standard no. 7 A

? ESD protection:

– HBM EIA/JESD22-A114A exceeds 2000 V

– MM EIA/JESD22-A115-A exceeds 200 V

? Specified from -40 °C to +85 °C and -40 °C to +125 °C

3 Applications

? Motor control

? Delay circuits

? Precision timing

? Domestic appliances