Sierra Semiconductor SC11003CM Full Duplex Single Chip Modem

The SC11003CM is a full‑duplex, Bell 103‑compatible, 0–300 bps single‑chip modem in a 20‑pin SOIC package, designed to operate from a single +5 V supply. On‑chip blocks include the FSK modulator and demodulator, high‑ and low‑band filters, and a line driver with a hybrid for directly driving a 600‑ohm telephone line, with CMOS switched‑capacitor filters providing the analogue front‑end. It also supports on‑chip analog loopback for test and diagnostics and is intended for embedded modem use in terminals, small business computers, and industrial control systems, including built‑in diagnostics within electronic equipment. The 20‑pin SOIC SC11003CM variant aligns with the Sierra SC1100 family packaging for single‑chip modem applications.