A quick one today, we’ll be looking at the Huawei E220 HSDPA USB Modem which is a USB modem, kind of similar to the Telstra one shown a few weeks ago except it only supports 3G (and not NextG) networks with no external antenna support.
A few plastic clips and 1 screw later and we’re in.
This time we did have some RF shields around all of the important chips. We seem to have a large 22mF (22000uF) 4.5V supercapacitor, I think this one is the largest I’ve seen on any PCB, this board must have some serious current spikes. There’s a Samsung logo on the PCB so I’m guessing they designed this board. There are a few little RF chips about.
There does appear that there is an external antenna connector after all, although there is no large PCB or SMD chip antenna you normally see, it’s just a small patch antenna with exposed copper (no antennas are present on the case).
Edit: It appears I missed a small plastic piece with the antenna which would connect to the exposed PCB pad.
It looks like this design uses the Qualcomm MSM6280 SoC and Qualcomm PM6650 power management chip which is the same as the Telstra USB.
We have the Qualcomm RTR6250 + RFR6250 which are Multiband UMTS/GSM RF chips, this dual chip solution gives quad-band GSM transceiver supporting 850/900/1800/1900MHz plus UMTS on 1900 or 2100MHz.
There is a Anadigics AND0041 Power Amplifier which can output 35.5dBm on GSM 850/900MHz and 33.5 dBm on GSM 1800/1900MHz.
Lastly we have some Samsung K5D1258DCA memory.
And that’s all.
Very Good. I like it!