General Description
The Supertex HT18LG and HT19LG are electronic line switch circuits that replace the mechanical hook switch contact or a discrete hook switch in a telephone handset or modem. They switch the positive side of the telephone line using control inputs that are referenced to the negative side of the line. In their off state, they can withstand 350V on the positive input. In their on state, they have a maximum series resistance of 18Ω.

Features
► 350V breakdown voltage
► 18Ω maximum switch resistance
► Current limiting protection
► Operates at 2.3V input

Applications
► Telephone handsets
► Modems
► Fax machines
► Answering machines
► Remote meter reading
► Telephone interface products