Let's Play: Name that SMD component

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#1
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Hi folks,

I was cleaning out the upstairs and found a usb device left here by a past tenant. I have no use for it in it's current state so decided to harvest the components from it. It's a microsoft sidewinder strategic commander:
http://www.amazon.com/Microsoft-...

I'm happy that so far I've recovered:
-An intact USB cable
-12 momentary push switches (score!)
-6 amber 3mm LEDs and 1 red 3mm LED
-Two trimpots
-1 resonator (not sure the frequency)
-a variety of connectors I should be able to reuse

What I was REALLY hoping I would find is a couple of 3v6 zener diodes to use with AVR to USB project for the D+ and D- lines.

So here's the question. On the main board coming off of the D+ and D- usb lines there are a couple of smd parts labeled FB1 and FB2. Any idea what these are? I have tried some multimeter tests and can't figure it out.

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a picture maybe?

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ESD protectors most likely? Something like the CR1 and CR2 on the Atmel USB key demonstration.

There are pointy haired bald people.
Time flies when you have a bad prescaler selected.

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Ferrite Beads likely for EMI suppression

2 terminal devices (like a resistor or cap), probably black or dark grey in colour with no other markings.

Writing code is like having sex.... make one little mistake, and you're supporting it for life.

Last Edited: Mon. Mar 24, 2008 - 03:59 PM
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FBn are very probably ferrite beads to suppress noise from the USB device. If electrical noise can get onto the USB cable, the cable becomes an antenna, "transmitting" the signal.

FYI, "zeners" are rarely used for transient suppression on USB because they have too much capacitance (MUCH more than you would expect, especially for the low voltage ones).

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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bloody-orc wrote:
a picture maybe?

Here's the picture.

Looks like lots of other input while I was busy taking a picture. Thanks for playing the game folks! (you're all winners in my book :wink: )

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Yup....

Ferrite Bead.

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net