Globalstar STX3, User Manual

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DEV KIT SCHEMATIC
The schematic is shown in Appendix A. The schematic consists of 9 pages organized with pages 3-5 for the circuitry
on the Transmitter board and pages 5-9 for the circuitry on the Main board. The descriptions below explain a high-
level description of each schematic page and its associated circuitry:
1.
Title Page
(page 1)
Includes notes on changes between the revisions of the schematic and the Table of Contents for the schematic.
2.
Block Diagram
(page 2)
Hardware architecture of the boards with interfaces to each of the boards.
3.
STX3 Transmitter module
(page 3)
This includes the STX3 transmitter with interface circuitry. All of the circuitry on this page is located on the
Transmitter board.
4.
RF Power supply
(page 4)
The power supply dedicated for the RF section of the STX3 module. The buck/boost power supply is enabled
and disabled by the STX3 module during transmission. The power supply is disabled when the STX3 is not
transmitting. Review the STX3 data sheet on details regarding time the RF power supply is enabled. All of the
circuitry on this page is located on the Transmitter board.
5.
Interface Connector and Expansion
(page 5)
This page includes the interface headers between the Transmitter board and the sockets on the Main board.
Also, included are the expansion header connected to the Nordic processor and a header that interfaces directly
with the STX3 module.
6.
BLE Nordic processor
(page 6)
This page includes the Nordic BLE processor, BLE chip antenna, processor controlled LED’s, SWD JTAG header,
reset button, user button, and all supporting components for the processor. All of the circuitry on this page is
located on the Main board.
7.
Sensors
(page 7)
The sensors include 3 axis accelerometer, humidity/temperature sensor, and analog adjust resistor
potentiometer. All the circuitry on the page is located on the Main board.
8.
USB and Power Input
(page 8)
The USB port provides power to the Dev Kit and allows for terminal communication to the Nordic processor. All
the circuitry on this page is located on the Main board.
9.
Power Supply
(page 9)
This is the main power supply for the Dev Kit and converts the USB 5V power to 3.3V. The 3.3V from this supply
is used by Transmitter and Main board. On the Transmitter board it supplies the logic voltage for the STX3
module, and supplies voltage for all of the circuitry on the Main board. Please note the 3.3V voltage does not
supply power to the RF transmitter of the STX3 module on the Transmitter board. All the circuitry on this page is
located on the Main board.