DS_1x66B_001
73M1866B/73M1966B Data Sheet
The Line-Side Device (73M1916) consists of:
1. Digital Sigma Delta Modulator
2. Transmit Analog Front End
3. Receive Analog Front End including Sigma Delta Modulator
4. Sinc3 Filter (Sinc3)
5. On-chip Line Interface Circuit
6. Line-Side Barrier Interface Circuit (LSBI)
Received data from a host connected to the PCM bus is interpolated from the sampling frequency of
8 kHz or 16 kHz (for PCM encoded streams) to twice the sampling frequency. The control information is
multiplexed with the audio stream signals and transmitted across the isolation barrier to the Line-Side
Device. In the Line-Side Device, the two streams are separated and the audio signal is converted to
analog for transmission to the line.
An audio stream received at the analog line input pins is converted to a serialized data stream and, along
with status information such as line condition from the Auxiliary Analog to Digital Converter, is transmitted
over the isolation barrier using the pulse transformer. The data is extracted with status information being
transmitted on the SPI. The audio stream is sent to a host using the PCM bus.
The 73M1x66B is an enhanced version of the 73M1966 that includes the additional functionality of finer
resolution of transmit and receive gain, receiver DC offset subtraction and support for T-1 PCLK
frequencies.
Rev. 1.6
7
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
