Where components are placed on the Librem 5 boards

Here is my attempt to identify where the components are placed on the Librem 5 boards:

I’m not sure about the Microchip USB2642 USB 2.0 Hub & Flash media card controller, because it has the right number of pins and is the right size, but it doesn’t look like a QFN package. The other one that I’m not sure about is the Texas Instruments TPS65982 USB Type-C and USB PD controller, but it looks like the right size and package type.

I can’t find these chips:

I’m guessing that the WM8962 is the small chip to the right of the i.MX 8M Quad, and the other two are underneath the two metal shields. The W25Q16JVUXIM TR is pretty distinctive with an SOIC-8 package, so I’m sure it is hidden under the shielding, but the WM8962 and BQ25895 are hard to tell apart visually (especially with these poor quality photos of the boards).

One interesting thing that I hadn’t noticed before is that the external connector has inputs labeled as NFC_EN (pin 6) and NFC_IRQ (pin 14) on page 14 of the schematics, so maybe NFC can be added in the future.

Another thing that I didn’t notice before is the two white LEDs on the USB-C daughter board. Has anybody noticed a white light near the USB-C port?


So (if no other way around), do you think that the TPD6S300A might be included as well? As it is written: “Once the power adaptor sees the dead battery resistors of the TPD6S300A, it applies 5 V on the V BUS pin. This provides power to the TPS65982, turning the PD controller on, and allowing the battery to begin to charge. However, this application requires 100 W charging in dead battery mode, so V BUS at 20 V and 5 A is required. USB PD negotiation is required to accomplish this, so the TPS65982 needs to be able to communicate on the CC pins.” In short, it provides additional support to the first generation of USB-C chipset from Texas Instruments (TPS65982):

@nicole.faerber, @Kyle_Rankin,
I would really appreciate it, if Purism would release detailed photos of the assembled PCBs in Evergreen and its x-rays. If Purism doesn’t want to destroy a board by ripping off the metal shields that cover the chips, at least release good photos of the bare boards before they are assembled, because it is easy to tell where each IC will be placed by looking at the pads in a bare board.

The fact that Purism releases its schematic is an important selling point for people who want to verify that no tampering has taken place in their phone, but it is very hard to verify. All we have at this point are blurry, low-resolution photos of the Dogwood PCBs and x-rays of the Birch PCBs, which are out-of-date, because the position of nearly every chip was changed in Dogwood. I noticed some changes between Dogwood and Evergreen as well, so it would be very helpful to have up-to-date photos.

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The 24 pin external connector appears to not be used right now, but I find it exciting that Purism was thinking about future expandability with I2C, UART, SPI Flash and NFC, when Purism designed the Librem 5’s boards.

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This appears to be the 3GB DRAM module for the L5 ( MT53E768M32D4DT-053 WT:E ):


Based on the latest communication from Todd Weaver, do you think this is the 4GB DRAM module for the L5 USA? Micron MT53E1G32D2NP-046 WT:A :


The physical layout of the pinouts between the two chips look identical.

I wonder if a hack could be written for the L5 USA that allows system access to that additional 1 GB of DRAM.

There are other questions here - will L5s in October 2021 also be using the newer 4GB DRAM as the 3GB part is now obsoleted, or does Purism have a cache of the older parts to use up?

Maybe that is the 4GB RAM being used, but the alternate part listed in the schematics is Micron MT53B1024M32D4NQ-062. Both are out of stock, so it is hard to know what Purism is using in the L5 USA.

As for enabling that extra 1GB RAM, I don’t have any idea if it is possible or not.

It’s interesting that Mouser indicates that the MT53B1024M32D4NQ-062 is obsoleted and not available ( https://www.mouser.com/ProductDetail/Micron/MT53B1024M32D4NQ-062-WTC-TR?qs=j%2B1pi9TdxUYEXrC1vu%2Fxyg%3D%3D )

while Mouser also indicates that the other alternative 4GB part I listed above ( https://www.mouser.com/ProductDetail/Micron/MT53E1G32D2NP-046-WTA?qs=wnTfsH77Xs7Q3fW8goEfJQ%3D%3D ) is a new product (although currently not in stock with 26 week lead time for ordering).

Only Purism knows, I guess.