Pi 2 Design Mercury Streamer, Hardware Reference Manual – P8
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3
OVERVIEW
3.1
INTRODUCTION
The Mercury Streamer, designed and manufactured by PI 2 Design, is a Compute
Module 4 based device designed for Professional, Studio Grade, Digital Audio
Streaming. The Mercury Streamer converts the Compute Module 4 I2S Interface to
High Definition Digital Audio Coax, OPTO and Balanced XLR. These multiple,
simultaneously active digital audio outputs allow the Mercury Streamer to optimally
interface with virtually any High Performance DAC on the market.
The major features of the Mercury Streamer are as follows:
•
COMPUTE MODULE 4 -
This latest module from the Raspberry Pi Foundation provides 4 High
Performance ARM Cores, Dual 4K HDMI Output, PCIe x1, Gigabit Ethernet
and more.
•
M.2 2280 SSD -
A Standard M.2 Socket is provided for nVME Storage via the CM4 PCI Express x1
Link. The socket supports both “M” Key and “B” Key devices.
•
GIGABIT ETHERNET -
A standard RJ45 Provides the interface to the CM4 Gigabit Ethernet I/F.
•
DUAL EXTERNAL USB2.0 -
This connector provides two USB2.0 Host Ports.
•
INTERNAL USB -
A vertical USB2.0 Connector is provided to interface with LCD Touch Screens for
Internal display-based systems.
•
EXTERNAL HDMI -
One 4K HDMI Connector allows access to CM4 HDMI Output 0.
•
INTERNAL HDMI -
A vertical HDMI connector allows access to CM4 HDMI Output 1 for Internal
display-based systems.
•
AES TRANSMITTER –
The industry standard WM8804 converts the CM4 I2S stream to AES3/SPDIF
formatted data at 24-Bit up to 192Khz Frame Rate
•
AES COAX OUTPUT –
A 1:1 Isolation Transformer provides Bit Perfect Impedance Controlled
Coaxial Transmission of the Digital Audio Data @1V AES Standard Level.
•
AES BALANCED OUTPUT
– An RS-485 Transmitter coupled with a 1:1 Isolation Transformer allows
the transmission of balanced audio data via the Professional Audio Standard XLR Connector
•
TOSLINK OPTICAL OUTPUT –
Isolated Optical Transmitter Drives Consumer Level DAC’s
•
SPDIF COAX OUPUT -
A 1:1 Isolation Transformer provides Bit Perfect Impedance Controlled
Coaxial Transmission of the Digital Audio Data @0.6V Consumer Standard Level.
•
DIFFERENTIAL I2S OUTPUT –
An LVDS Differential Transmitters is used to drive the I2S Bus over
a standard HDMI Connector. The Pinout conforms to the PS Audio Standard.
•
HIGH RESOLUTION CLOCKS –
A pair of Ultra-Low Noise NDK NZ2520SDA oscillators allow the
WM8804 to operate in non-PLL mode for the lowest possible noise.
•
ULTRA-LOW NOISE LDO’s –
Separate Ultra-Low Noise LT3042 LDO’s (0.9 uV noise and 80 dB
PSRR) are used to supply the WM8804 Transmit Section and the NDK Clock’s. Additionally, these
are fed from an LT2941 LDO used as a 5V pre-regulator. This allows the entire power chain to be
linear (assuming an external linear supply is used).
•
LOW NOISE PCB LAYOUT
– Constructed with 4-layer Split Ground PCB with noise reduction
techniques refined from years of High-Speed Mixed-Signal Design work.
•
EXTRUDED ALUMINUM ENCLOSURE –
Rugged, Aircraft Grade Aluminum, Anodized for Scratch
Resistance
