60Hz Long Interval Counter


The ELM381 is a digitally configurable, multi- stage counter circuit in a single 8 pin package. When connected to a 60Hz source, four time periods from one hour to one week are possible, as shown in Table 1 below.

Although the circuit has been optimized for a 60Hz input frequency, it is capable of being operated over a very wide range of frequencies. Of particular interest is the ability to interface directly to very low frequencies with varying waveforms due to the use of a Schmitt trigger input circuit.

The ELM381 provides two outputs – a standard 50% duty cycle divider output, and a momentarily pulsed output. The pulse output is useful for audibly or visually signalling the beginning of a time period, or as a trigger for other circuitry. Refer to the Example Applications section of the data sheet for two typical circuits.


  • Long term (daily or weekly) event timers
  • Missing event detectors
  • Automatic shutoff circuits


  • Low power CMOS design – typically 1mA at 5V
  • Wide supply range – 3.0 to 5.5 volt operation
  • Digitally selectable delays
  • Schmitt trigger circuitry on the clock input
  • Completely static operation
  • Long term accuracy with line frequency clock
  • High current drive outputs – up to 25 mA
  • Reset input provided with a pullup resistor

Connection Diagram

( PDIP or SOIC, top view )
ELM381 connection diagram

Block Diagram

ELM381 block diagram


The ELM381 data sheet (ver A, 31K):

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Quantity Pricing

The following are the unit prices, as you vary the quantity purchased:






All prices are in Canadian dollars. We use the total number purchased (ELM381P + ELM381SM) for the calculation.


Select the desired integrated circuit package type, then the quantity desired, before adding it to your shopping cart. Quantity discounts will be applied as appropriate.


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