The SC11280 is a complete DTMF transmitter/receiver fabricated in Sierra's proprietary 3 micron CMOS technology. It features excellent performance with low power dissipation and high reliability. The device includes an internal oscillator, adjustable guard time, and automatic tone burst mode.
The transceiver utilizes a switched capacitor filter for the transmitter to ensure low distortion and high accuracy. The receiver is based on industry standards and employs digital counting techniques with a complex averaging algorithm to protect against tone simulation by extraneous signals like voice.
The device operates using a single 5 Volt supply.
It is directly compatible with the 6800 series microprocessors.
The clock output operates at a frequency of 3.5795 MHz.