Librem 5 Phone – Chestnut

The sections on this page contain information about the Chestnut revision of the Librem 5 phone.

Improvements over Birch

Phones in the Chestnut shipment have these improvements over those in the Birch shipment:

  • The red LED always indicates the charging state, regardless of whether or not the PMIC is powered. (It can illuminate when the phone is “off”.)
  • Fixed an issue where the TPS65982 was not entering its APP mode when VBUS was presented before the PMIC’s BUCK6 VDD_3V3 rail. This means that rapid charging occurs regardless of whether the TPS65982 is first powered via USB or via the battery – rapid charging always works.
  • The microSD card is now read-write.
  • The USB 2.0 D+/D- is now routed directly to the USB-C receptacle so it does not rely on the TPS65982 entering its APP mode to use the data interface. This prevents an extremely unlikely but potential brick situation, which could only really be achieved on a Birch unit if done deliberately.
  • Improved the WWAN kill switch inrush current such that using a PLS8 M.2 module would not cause the device to reset if you flip the switch off and back on.

Quick Start Guide

The version of the Quick Start Guide included with the phone can be downloaded: Librem5-Quick-Start-1.1.0.pdf

Components

System on Chip and Peripherals

Audio

  • Wolfson Media WM8962
  • Headphones and external microphone via CTIA-configured 3.5mm jack
  • Loudspeaker

Battery

Bluetooth, Wi-Fi, WWAN

  • Bluetooth I2S interface
  • Bluetooth (SDIO)
  • RedPine WiFi/BT M.2 module on SDIO
  • Broadmobi BM818-E1 or BM818-A1 WWAN module

Display

  • Mantix MLAF057WE51 MIPI DSI LCD panel: 720x1440 pixels and touch controller

GNSS

  • Teseo-LIV3F multiconstellation GNSS receiver (UART2 interface and antenna)

Hardware Kill Switches

  • Diodes Incorporated Power Switch [datasheet]
    • WWAN (Modem)
    • WiFi/Bluetooth
    • Microphone and Camera

nano-SIM and microSD Cards

  • Combined microSD and nano-SIM slot

Push Buttons

  • Power
  • Volume up
  • Volume down

Sensors and Motors

Test Points

The 15 test points for UART1, UART2, JTAG, and the BOOT_MODE0/1 pins can be found below the WLAN module on the rear of the phone, as shown with the rear cover removed.

See a larger version of this image

The USB test points are located in the recessed area above the battery compartment.

USB

Schematics

The following schematics are available: