ELM446

Features:

• Low power CMOS design
• Wide supply range - 3.0 to 5.5 volt operation
• 3.58MHz crystal controlled operation
• Generates both 50Hz and 1Hz references
• Low parts count
• Complementary 50Hz outputs
• High current drive outputs - up to 25 mA


Application

• Stable 50Hz reference
• Master oscillator for clock / timekeeping functions
• Decimal based time reference for easier period calculations


Specifications

Storage Temperature....................... -65°C to +150°C
Ambient Temperature with
Power Applied....................................-40°C to +85°C
Voltage on VDD with respect to VSS............ 0 to +7.5V
Voltage on any other pin with
respect to VSS...........................  -0.6V to (VDD + 0.6V)

Note:
Stresses beyond those listed here will likely damage the device. These values are given as a design guideline only. The ability to operate to these levels is neither inferred nor recommended.


Description

The ELM446 is an 8 pin digital divider integrated circuit, that provides both 50Hz 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 50Hz signal. For convenience, a complementary 50Hz signal is also provided. This signal is then further divided to provide a 1Hz signal output.

A reset input is provided to restart the internal counters, if desired. An active low signal on this pin will also force all of the outputs to an open or tristate condition.