Definitive Tracking Antenna Design Decisions

Tracking Antenna PCB Peripherals

The following peripherals are planned to be supported by tracking antenna PCB.

• Telemetry Receiver (only one will be used)

  • XBEE

    • https://www.sparkfun.com/datasheets/Wireless/Zigbee/XBee-Datasheet.pdf

    • Operating Voltage: 3V3

    • Max Current: 250mA

  • RFD900

    • https://fcc.report/FCC-ID/2ADLE-900X/4165637.pdf

    • Operating Voltage: 5V0

    • Max Current: 1A

• 9-Axis Sensor

  • BMX160

    • https://www.mouser.com/pdfdocs/BST-BMX160-DS000-11.pdf

    • Operating Voltage: 3V3

    • Max Current: 1.6mA

• GPS

  • TBS M8.2

    • https://content.u-blox.com/sites/default/files/products/documents/u-blox8-M8_ReceiverDescrProtSpec_UBX-13003221.pdf

    • Operating Voltage: 3V3

    • Max Current: 21mA

• Motor

  • 2x Servo (voltage and current are for individual servo)

    • https://www.servocity.com/2000-series-5-turn-dual-mode-servo-25-2-torque/

    • Operating Voltage: 5V0

    • Max Current: 2A

• Low Battery Light

  • Unknown

    • (insert link)

    • Operating Voltage: 12V0

    • Max Current:

• SD Card

  • N/A

• Nucleo

  • NUCLEO-L552ZE-Q

    • https://www.st.com/en/evaluation-tools/nucleo-l552ze-q.html

    • Operating Voltage: 5V0

    • Max Current: 500mA

• VTX

  • Unknown

    • (insert link)

    • Operating Voltage: 12V0

    • Max Current: 3A

Block Diagram

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VBAT-5V @ 5A Buck Converter

VBAT-12V @ 3A Buck Converter

Note typical component values for 12V Vout and 2.1MHz switching frequency. A 2.1MHz switching frequency will provide us with higher switching losses (reduced efficiency) but a faster transient response and lower output voltage ripple (as well as a smaller inductor and output caps).

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Graph below represents VIN to 5V Vout efficiency at 2.1MHz (not fully representative of our scenario). At loading conditions of 1A-3A we can potentially expect efficiency values of 80%-90% based on VIN and loading conditions.

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