The 73M1866B and 73M1966B use the Teridian patented Data Access Arrangement function (MicroDAA®) designed exclusively for Foreign-Exchange-Office (FXO) in Voice-over-IP (VoIP) applications. These devices provide much of the circuitry required to connect PCM formatted voice channels to a PSTN via a two-wire twisted pair interface. The package options provide the necessary functional programmability and protection required for easy worldwide homologation. The family of devices consists of the 73M1866B and the 73M1966B. The 73M1866B MicroDAA is the world’s first single-package silicon Data Access Arrangement (DAA). Suitable applications for the 73M1866B and 73M1966B devices include VoIP equipment that must provide connectivity to the PSTN for purposes of guaranteeing emergency service calling, redundancy for supplementary connectivity for voice, and maintenance services. The 73M1966B device set consists of the 73M1906B Host-Side Device that provides digital data, control interfaces and power to the 73M1916 Line-Side Device. These devices are based on an innovative and patented technology, which sets new standards in reliability and cost. A small pulse transformer forms a digital isolation barrier, transferring both power and data to the PSTN line-side components. This method results in reliable operation.
The 73M1866B and 73M1966B are Teridian MicroDAA devices that provide FXO functionality for VoIP equipment, connecting PCM voice channels to the PSTN. They include a host‑side and line‑side device linked by an isolation barrier pulse transformer.
The datasheet details pinouts, electrical specifications, SPI and PCM highway interfaces, analog and digital gain settings, and application information such as call progress monitoring and line sensing functions.
| Isolation barrier frequency | 768 kHz |
|---|---|
| Data transfer rate (8 kHz sampling) | 1.536 Mbps |
| Operating temperature range | -40 °C to +85 °C |
| Maximum analog gain | +6 dB (transmit), +3 dB (receive) |
| Digital gain range | –18 dB to +7.375 dB in 0.125 dB steps |
| SPI daisy‑chain support | up to 16 devices |
The isolation barrier operates at a frequency of 768 kHz.
Up to an additional +6 dB of analog gain can be applied to the transmit path.
The SPI interface supports daisy‑chain connections for up to 16 devices.