TCM1520AD — high-voltage detect & 1 MΩ standby

TCM1520AD is a Texas Instruments ring-detector IC built for telephone interfaces. It senses typical ring signals (about 40–150 V, 16–68 Hz) while drawing ~1 mA, so it won’t load the line. Standby input impedance is around 1 MΩ to avoid disturbing DTMF or voice traffic. An internal 150-V bridge configuration and a built-in 5 V series regulator simplify your front end. The output drives TTL, NMOS, or CMOS logic directly, easing optocoupler or MCU interfacing. Need TCM1520AD for maintenance or new builds? Request a fast quote for pricing, stock, and U.S. shipping today.