
Elm Electronics
Description
The ELM337 provides a convenient means to interface standard photocells or light dependent resistors (LDRs) to digital logic circuits. It provides an input comparator with hysteresis, line frequency filtering, digital delays, and high current output drivers all within the one 8 pin package.
Three mode setting pins configure the ELM337 for pulse or continuous output and for a delay on
change of from 1 msec to 10 minutes. The transition threshold is set with a single external resistor, simplifying designs and minimizing costs.
FEATUREs
• Low power CMOS design - typically 1mA at 5V
• Operates from 3V to 5.5V
• No external timing elements required
• Low parts count
• Digitally selected delays of up to 10 minutes
• Pulsed or continuous outputs
• Internal line frequency filtering
• High current drive outputs - up to 25 mA