Teardown Tuesday - USB Wireless Dongle

This one came to me pre-torn-down. While walking on Westlake near my office I looked down and spied something that was not like the sidewalk. It was shiny but wasn't money.The grain of rice wasn't from the sidewalk obviously.The other side makes this clearer:You can clearly see the footprint of the USB plug. The antenna from the other side is, unsurprisingly, on the blank area with the date code. It's unsurprising because you don't want other devices either blocking or detuning the antenna so you can get the best performance.A biit of Googling and I can figure out the protocol it speaks.The "big" BGA chip next to the antenna is a model BCM2046. This turns out to be a Broadcom Bluetooth controller.From looking around I couldn't find a pure datasheet, but I at least came across a brochure. It seems that the chip handles not just the Bluetooth side of the equation, but the USB side as well. Makes for a sweet little integration!The block diagram on the brochure makes the function of the chip on the other side clear: it has to be a serial ROM of some variety.This is a H024 2DB 1 mounted exactly underneath the Bluetooth controller. While the Google could not come through for me, I'll take it at faith that this is in fact the ROM.The last chip on here is a five-leaded jobbie marked A1T51. Again I can't find any reference to this part, but I would be surprised if this wasn't a DC regulator of some type.The last active part of the circuit is the 26MHz crystal that provides the clock for the Broadcom Bluetooth chip.The rest of the circuit is populated by some of the tiniest passives I've ever seen. We have some 0402 resistors, capacitors and a couple inductors. You can see the lead-up to the antenna is a series of capacitors and inductors which forms a matching network for the antenna.Yes, I did measure them. They came to 0.04" x 0.02". Hence: 0204.The crazy thing is there are passives that are 1/4 the size in each direction! 01005 components are tiny! They are 0.010" x 0.005"!. That is 5 thousandths of a freaking inch.Oh, and the Broadcom Bluetooth chip. It's 5mm on a side and has 65 pins (well, solder balls) on the bottom!I know, this wasn't overly informative... I just wanted to use my macro lens on an item of found hardware.  :-)