Description

The ELM440 is an 8 pin digital divider integrated circuit, that provides both 60Hz and 1Hz outputs from a common 3.58MHz NTSC colourburst crystal.

Externally, the designer need only provide the crystal and two appropriate loading capacitors, as well as a suitably bypassed power supply. Internal oscillator circuits then use this reference frequency to precisely derive a stable 60Hz signal. This signal is then further divided to provide a 1Hz output.

Features

• Low power CMOS design

• Wide supply range - 3.0 to 5.5 volt operation

• Generates both 60Hz and 1Hz references

• Automatically synchronizes to the line frequency for long term stability, when it’s available

• Uses a standard 3.58MHz crystal for the time reference if there is no sync input

• High current drive outputs - up to 25 mA

Applications

• Stable 60Hz and 1Hz reference sources

• Master oscillator for clock / timekeeping functions

• DC powered backup 60Hz reference signal