SBAS495D June 2010 – August 2021 PCM9211
PRODUCTION DATA
Up to 12 single-ended S/PDIF input pins are available. Two of the S/PDIF input pins integrate coaxial amplifiers. The other 10 pins are designed to be directly connected to CMOS sources or standard S/PDIF optical modules. Each of the inputs can tolerate 5-V inputs.
The DIR module in the PCM9211 complies with these Digital Audio I/F standards:
In addition, the DIR module within the PCM9211 also meets and exceeds jitter tolerance limits as specified by IEC60958-3 for sampling frequencies between 28 kHz and 216 kHz.
Each of the physical connections used for these standards (optical, differential, and single-ended) have different signal levels. Take care to make sure that each of the RXIN pins is not overdriven or underdriven, such as driving a coaxial 0.2-VPP signal into a CMOS 3.3-V input.
RXIN0 and RXIN1 integrate coaxial input amplifiers. This architecture means that they can be directly connected to either coaxial input (or RCA/Phono) S/PDIF sources. They can accept a minimum of 0.2VPP. They can also be connected to maximum 5-V TTL sources, such as optical receivers.
Consideration should be made for electrostatic discharge, or ESD, on the input connectors.
RXIN2 to RXIN11 are 5-V tolerant TTL level inputs. These inputs are typically used as connections to optical receiver modules (known as TOSLINK™ connectors).
RXIN8 through RXIN11 are also part of the MPIO_A (Multipurpose Input/Output A) group. These I/O pins can either be set as S/PDIF inputs, or reassigned to other functions (see the Section 7.3.8.8 section). To configure MPIO_A as S/PDIF inputs, set Register MPASEL[1:0] to 00.
Typically, no additional components are required to connect an optical receiver to any RXIN pin. However, consideration should be given to the output characteristics of the specific receiver modules used, especially if there is a long printed circuit board (PCB) trace between the receiver and the PCM9211 itself.
For differential inputs (such as the AES/EBU standard), differential to single-ended circuitry is required.