Power Supply

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The amplifier and the controller can be powered by a 5V USB power supply. Both boards have a mini USB jack. The mini USB jack of the STM32F4DISCOVERY board cannot be used to supply the system. This jack is only used for programming the STM32F4DISCOVERY board. The +5V line of both boards are connected via the connection cable. It is neither necessary nor recommended to power the system at both ends. We recommend to power the system at the controller site. When the boards get power the red power indicator LED on the amplifiers lights up. On the controller board the power on LED of the STM32F4DISCOVERY board and some of the other LEDs will turn on. The power consumption of the amplifier and controller is about 40 mA and 400 mA, respectively.

The system can also be powered over the Ethernet connection cable if the J0006D01BNL RJ45 Ethernet Jack from Pulse Electronic is used. This Power over Ethernet (PoE) technique uses pin 7 for +5V and pin 8 for ground. To inject the power, a simple PoE injector is needed. As only 5V is used as supply voltage, the network cable must not be longer than a few meters. If the voltage drop is too high, you can try to inject up to 6V. Don’t use higher voltages! Note: This pseudo PoE is not compatible with the official IEEE standard 802.3af!