HiRel/CanSat/Slave Power
From FSI
|
This board powers the CanSat system either from a battery or from an USB connector.
| CanSat Slave Power | Schematic | Description |
|---|---|---|
 |
CanSat Slave Power v2.0 Schematic PDF | LDO 5V -> 3V3: v1: SC189XSKTRT v2: AP7361-FGE-7 |
It additionally provides a serial port over USB, 4 switches and 2 LEDs.
Power inputs
The CanSat system has 3 possible power sources:
- a micro-USB connector on the power supply board
- a battery connector on the power supply board
- a micro-USB connector on the microprocessor board
Only one of these should power the system with 5 V. Jumpers are provided in order to select the actual power source. This 5 V is distributed to all the boards on the top connector disk.
The power board generates 3.3 V from 5 V. The 3.3 V is distributed to all the boards on the bottom connector disk.
Power usage
The 5 V is used by:
- the power supply board for generating the 3.3 V
- the sensors board for the Max11300 together with the temperature and pressure sensors
The precision of the 5 V is given by the components' requirements:
- the DC/DC converter needs 2.9 V ÷ 5.5 V
- the Max11300 mixed-mode I/O interface needs 4.75 V ÷ 5.25 V
- the pressure sensor needs 4.75 V ÷ 5.25 V
- the temperature sensor needs 2.5 V ÷ 5.5 V
The 3.3 V is used by:
- the FPGA
- the XBee module
- the humidity sensor on the sensors board
Board connectors
Additionally to the Power supply, the power board provides:
- 4 switches
- 2 LEDs
- a serial port
The connection to the module is done through following pins:
| name | pin | dir | description |
|---|---|---|---|
| TxD | b1 | out | serial link TxD |
| RxD | b3 | in | serial link RxD |
| Led_0 | b5 | in | user LED 0 |
| Led_1 | b7 | in | user LED 1 |
| switch_0 | b2 | out | DIL switch 0 |
| switch_1 | b4 | out | DIL switch 1 |
| switch_2 | b6 | out | DIL switch 2 |
| switch_3 | b8 | out | DIL switch 3 |
BOM
| Device | DigiKey Part No | Description | Quantity |
|---|---|---|---|
| 10104111-0001LF | 609-4053-1-ND | GDH04S04 SWITCH DIP HALF PITCH 4POS 24V | 1 |
| 1571983-5 | 450-1762-1-ND | FTDI IC USB FS SERIAL UART 28-SSOP | 1 |
| AP7361-FGE-7 | AP7361-FGE-7DICT-ND | DC-DC 5->3.3 ADJ | 1 |
| GRM21BR60J106ME19L | CAP CER 10uF 6.3V 20% X5R 0805 | 1 | |
| 08056D475KAT2A | 478-1416-1-ND | CAP 4.7uF 10% X5R 0805 | 1 |
| Resistance 0603 75k | 1 | ||
| Resistance 0603 24k | 1 | ||
| Resistance 0603 100 | 5 | ||
| LED 0603 green 2V2 15mA | 5 | ||
| GDS04S04 / 1825006-8 | 450-2162-ND | SWITCH DIP SLIDE 4POS SMD | 1 |
