power¶
Subsystem sheet /power of camera-gpio-interface-pcb, from the board recipe subsystems/power.subsystem.yaml.
USB power: the usb2_vertical block makes +5V from the USB-C receptacle's VBUS through its Schottky (the USB2 data pair is unused, the board has no MCU), and the 5v_to_3v3_tps73733 block makes +3.3V, the board's only logic rail, always on by construction as the InstrumentPort block requires; a power LED on +3.3V.
Board note: board-authored sheet, 2 parts
Notes¶
- +5V is used only for the three camera channels' Line 0 pull-ups (820 Ω to about 4.7 V, FLIR's 5 V / 1 kΩ opto drive) and as the VBUS reference of every ESD array (nine on the board). The budget is well under 100 mA (five LV541A, four LVC2G17, four LVC1G125, three LVC1G07, seven LEDs, pull-ups), so any USB port or wall adapter works; nothing reads the CC advertisement.
- The USB block's USB_D+, USB_D- and VBUS ports carry no-connect flags: the data pair is unused, and the board picks the rail up after the diode-OR Schottky as +5V_USB, named +5V here (the block's port name; the PWR_5V patterns match it).
- D201 through R201 (680 Ω) is the power LED on +3.3V. +5V and GND carry PWR_FLAG in this sheet because no power-output pin drives them here.
- Not chosen: 3.3 V from a camera's VOUT, which would force Line 2 back to VOUT, push the frame output onto the 36 µs opto line and make the board depend on which camera is plugged in.
Ports¶
The recipe's ports as the sheet symbol carries them, the root label each meets, and the net's class, MCU pin and meaning.
| Port | Shape | Wired to | Net | Class | GPIO | Meaning | |
|---|---|---|---|---|---|---|---|
+3.3V |
passive | shared | +3.3V |
/+3.3V |
PWR_3V3_NARROW | The only logic rail, from the TPS73733 on the power sheet; always on while USB is present, as the InstrumentPort block requires | |
+5V |
passive | shared | +5V |
/+5V |
PWR_5V_NARROW | VBUS after the USB block's Schottky (+5V_USB in the design record): the Line 0 pull-ups and every ESD array's clamp reference | |
GND |
passive | shared | GND |
/GND |
PWR_RETURN_LOCAL | Board ground; every BNC shell and camera pins 5 and 6 |
Blocks¶
The recipe's roles and the placements that fill them on this board.
| Role | Instance | Block | Lifecycle | Summary |
|---|---|---|---|---|
5v_to_3v3_tps73733 |
5v_to_3v3_tps73733 |
orb_weaver_private:5v_to_3v3_tps73733 |
routed | Clean 3.3 V linear regulator from a 5 V input rail using the TI TPS73733 fixed 3.3 V 1 A LDO. |
usb2_vertical |
usb2_vertical |
orb_weaver_private:usb2_vertical |
routed | USB-C USB2 device-port front end on a VERTICAL, top-entry receptacle: GCT USB4145-03-0070-C, OW-CONN-USB-C-USB2-SMD-VERT, 16P USB2-only, SMT contacts plus four through-hole shell legs, 7.46 mm tall. |
Glue¶
The subsystem's own parts and nets, drawn by the board around the blocks.
| References | Part | Value | Role |
|---|---|---|---|
D201 |
OW-MISC-APHHS1005CGCK |
APHHS1005CGCK | power LED on +3.3V |
R201 |
OW-PASS-RC0402FR-07680RL |
680 | power LED series resistor, about 1.8 mA |
| Net | Kind | Pins | Meaning |
|---|---|---|---|
+3.3V |
port | R201.1 |
the logic rail, from the LDO block; the LED hangs on it |
GND |
port | D201.1 |
the LED cathode |
| wire | D201.2, R201.2 |
the power LED's anode node |
Power flags: +5V, GND.