Internals

Power

There are 4 power rails:

1. STANDBY_3V3 - Always on (manual switch), supplied from MAX1837EUT33 regulartor (VCC 5V -> 3.3V)
   • system MCU
     • VCC
     • USB port
     • I2C pullup
     • Reset pullup
   • RTC
   • FUSB302BMPX (USB-C with power delivery)
   • Qwiic I2C
   • Power rails latch (enables other power domains)
   • SYSCTL UART 1 connector (keyboard)
   • W25Q32JVSS (Flash?)
2. VCC 5V - Supplied from charcher
   • MAX1837EUT33 (4.5V - 24V -> 3.3V) provides STANDBY_3V3
   • TPS5450DDAR when enabled via power latch provides 5V rail
   • TPS5450DDAR when enabled via power latch provides 3.3V rail
   • LM2830XQMFE/NOPB when enabled via power latch profides 1.1V rail
3. USB_VBUS - Power form USB-C port 1 (PD port)
   • VCHG Power to charger
4. +5V
   • AP22815A Power distribution switch; when enabled it powers USB_VBUS so any connected USB device for port 1 (PD port)
   • TLV320AIC3100 Audio codec for speaker and headphones
   • USB port 2 VBUS
   • TPD12S521 HDMI port
   • SoM (CPU card)
   • TUSB8041 USB Hub
   • Keyboard USB power
   • Internal USB port for flashing SYS MCU (Receptacle)