Power Supply

From Albatross

The power supply supplies a number of different voltages from which the system operates, including two 3 5V rails, and 2 3.3V rails. These may all be powered on or off seperately to conserver power. A description of the operation of each supply, and what it powers is listed below;

Supply Details

Each supply is identified by its net name on the schematic.

+5V

• 5V switching power supply (LM2594M-5.0)
• Powers
  • Gyro ADC
  • Gyroscopes
  • GPS (RF Antenna FIXME)

+5VLDO

• 5V precision LDO regulator (TPS7650)
• Chosen to provide both the supply and reference to certain analogue electronics on the board.
• Powers
  • Gyro analogue supply
  • Accelelometers
  • The analogue filters for the accelerometers and gyros.

+5LDOPRES

• 5V precision LDO regulator (TPS7650)
• A high precision supply was neccessacery because some sensors are ratiometric to the supply (e.g. the accelerometers) FIXME
• Powers
  • Pressure sensors
  • Pressure sensor ADCs

+3V3

• High current 3.3V switching supply (LM2596S-3.3)
• Powers
  • Snapper
  • FPGA
  • Other Sensors
    • Temperature sensors x2
    • Thermocouple interface
  • Communications radio
  • GPS

+3V3LDO

• 3.3V precision LDO
• The only supply which is always powered, and cannot be shutdown by the supervisor.
• Powers
  • Supervisor

Grounding

We maintain 3 primary grounds, DGND, AGND and PGND for the digital, analogue and power periphials respectively.

Certain analogue electronics are also very sensitive to EMI, so have dedicated ground planes (such as the GPS reciever)