tve
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EMW3165 photo

Wed Oct 28, 2015 5:05 am

In case someone is curious, here's a photo with the shield off. I have to admit that I was surprised by the number of discrete components!
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emw3165-photo2.jpg
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emilfr
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Re: EMW3165 photo

Wed Oct 28, 2015 8:58 am

Interesting indeed... I had only looked at the photo from the FCC certification before, but it's too low res to make anything out.
Can you make out the markings on the SPI flash, in the upper right corner? I'm curious as to the specific spi flash is used, the marking on the schematic doesn't turn up anything that I can be certain is the right one.

There is a 6 pin package in the lower left that I'm curious about as well.

The big IC on the right is probably the STM32F411CEY6TR_WLCSP49. The reason for thinking that is that it better fits the dimensions of a WLCSP49 package, that is 3.034 mm x 3.220 mm, and it's next to the RTC crystal. Also, it makes more sense to have the wifi chip closer to the antenna.

I annotated the photo, I hope you don't mind :) Also, can I add it to the WICED-for-EMW repository, with the documentation?
emw3165-photo2-annotated.jpg
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Maintainer of the EMW3162 and EMW3165 port of Broadcom WICED.
== Github == Gitter.im chatroom == WICED subforum == Getting started with WICED on EMW ==

-- Neither I nor the WICED for EMW project are affiliated with MXCHIP or Broadcom --

emwadmin
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Re: EMW3165 photo

Wed Oct 28, 2015 6:55 pm

The black 6-pin IC in the corner looks like it could be a SPDT RF Switch. I can't make out the markings to identify it, but I know Skyworks is pretty big in this market, so it could be one of theirs. I'm not all that sure why this would be included in the design since the antenna is strictly WiFi and not multiplexed with other RF (such as BTLE).

The second unidentified component is more than likely a passive RF low-pass filter. Again, visually identifying this to an exact part number is pretty tough, but to take a stab at it, I'd go with something from Johanson since they are big in this field, and the datasheet for their 2450LP07A0100 (http://www.johansontechnology.com/datas ... 7A0100.pdf) looks like it's got the same footprint.

Of course, MXCHIP has probably found Asian sources of these parts in order to keep costs low, but they are probably functional equivalents of the devices made by the big players I mentioned.

Murata makes a module with the same BCM43362 chip and the block diagram published on page 5 of their datasheet supports my assumptions that the unidentified parts are an RF switch of sorts and a low-pass filter. You can have a look at it here: https://electricimp.com/docs/attachment ... 1ZV1CD.pdf (electric imp flavor which includes on-board STM mcu)
and another version of it here:
http://www.mouser.com/ds/2/281/sn8000-8 ... 514133.pdf (murata flavor, no on-board mcu).

Hopefully my guess isn't too far off from the truth :-)

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emilfr
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Re: EMW3165 photo

Wed Oct 28, 2015 11:03 pm

Yeah, I think you might be right on the money there...
The second unidentified component is very probably a filter... you can so easily trace the path of the radio signal from the antenna selector resistors, through the unidentified component and all the way to the unidentified package in the corner.
With some squinting, I think I can see two separate traces from the broadcom chip to the blue smd components that lead to the chip you identified as SPDT RF switch.

I have spare modules... I need to get around to opening one up, one of these days...
Maintainer of the EMW3162 and EMW3165 port of Broadcom WICED.
== Github == Gitter.im chatroom == WICED subforum == Getting started with WICED on EMW ==

-- Neither I nor the WICED for EMW project are affiliated with MXCHIP or Broadcom --

tve
Posts: 9
Joined: Sun Oct 18, 2015 8:25 pm

Re: EMW3165 photo

Thu Oct 29, 2015 3:38 am

Emil, you're welcome to use the photo as you please.
Flash chip: 25L1606E / M1I-12G
Chip in bottom-left corner has FJ as markings, both with a dot over the top of the letter
The large rectangular chip is the BCM43362, the markings on the swuare STM chip are almost impossible for me to make out, I can just make out a 'F411CE'.
The narrow whitish chip near the bottom left has no markings, except that the lower half has an inset grey square.
The shield actually came off easily, I started with side cutters wanting to cut it off, but with a gentle half-bite I could pry the edge up just like that. After that it was just a matter of slowly going around the perimeter and prying the shield off. In the end it came off in one piece.

DHK
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Re: EMW3165 photo

Tue Nov 10, 2015 1:14 pm

I'm not all that sure why this would be included in the design since the antenna is strictly WiFi and not multiplexed with other RF (such as BTLE).

It is just a Tx/Rx RF Switch. BCM43362 has separate TX/RX pins.

emwadmin
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Re: EMW3165 photo

Tue Nov 10, 2015 6:37 pm

Excellent observation - that makes complete sense.


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