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