miniDSP Ltd, Hong Kong /
/ Features and specifications subject to change without prior notice
8
2.2
DC
POWER SCHEMES
The UMA-8-SP has 2 modes of operations when it comes to powering schemes:
USB self-powered:
A single USB connection to your PC/Mac suffices to provide power to the unit and stream
bidirectional audio simultaneously. In this mode, the UMA-8-SP will disable the amplifier due to the limited
current capabilities of USB power.
External 12V power supply
: In this mode, the UMA-8-SP will have the digital audio amplifier for up to
2x15Wrms.
2.3
I2S
EXPANSION HEADER PINOUTS
Headers J3 is provided for connection of I/O circuitry via I2S. The pinouts are shown in Table 1.
In the current firmware, none of the I2S in/out are enabled.
2.4
D
IGITAL
A
UDIO
A
MPLIFIER OUTPUTS
The onboard stereo digital audio amplifier outputs are available on a 3.81mm pitch removable Phoenix terminal
block. The below diagram shows the typical configuration (OUT 1 +, OUT1-, OUT2-, OUT2+)
2.5
A
DDITIONAL
I2S
USAGE NOTES
Note that I2S is not a “plug and play” protocol. It requires attention to technical details such as clocking and wire
layout. It is a solution for OEMs and
advanced
DIYers (or professionals) with suitable knowledge, skills and
measurement equipment.
Be sure to take the following precautions when designing your I2S interface and wiring:
General I2S usage notes
•
Unbuffered I2S lines must be kept short to ensure clock and data integrity.
OUT 2
OUT 1
