In this blog, I have done a teardown of very popular and cost effective Quectel EC200U GSM GPRS modem. I have already done several teardowns of GSM GPRS modems. Quectel EC200U supports LTE + 2G fall back, BLE, GPS option is also there.
Quectel’s EC200U is a series of the latest LTE Cat 1 modules optimized specially for M2M and IoT applications. It delivers maximum data rates of 10Mbps downlink and 5Mbps uplink.
Designed in a compact and unified form factor, the EC200U series is pin compatible with Quectel’s multi-mode LTE Standard EC20-CE, EC200S series, EC21 series, EC25 series, EG21-G and EG25-G, ensuring that it can easily migrate among compatible LTE modules.
The EC200U series also supports standard Mini PCIe packages to meet the needs of different industry applications.
It also support Open CPU architecture, that means you can build your application on top of Modem’s base firmware and you don’t need to use external MCU, this is a significant cost saving for high volume products.
I have used this Quectel EC200U modem is several customer project and the modem works well in all the sitaution’s ofcourse you need to handle a lot of things in software to make it work reliably.
Let us see how this modem is built, which SoC is used and what other chipsets are used for power supply and RF section.
For the teardown I had to sacrifice one modem development board as the shield of modem was soldered on the PCB and it was quite hard to remove. In the process I broke on of the inductor of the DC DC section on the module, anyways, that’s not a problem at all.
The main processor used is from Unisoc, this we saw on Quectel EC600G teardown as well.
It used UniSoC, UIS8910DM
UIS8910DM is an advanced system-on-chip solution integrated CAT1bis/GSM/GPRS modems.
Building on the success of UNISOC’s current solutions, the UIS8910DM integrates RF transceiver and Bluetooth RF for low cost.UIS8910DM supports plenty of peripherals such as SDIO, UART, I2C, SPI, I2S, MIPI CSI, and GPIOs.
Full custom power management chip provides power to SOC and all peripherals. To meet the increasing popular power-saving requirements without the use of additional hardware, UIS8910DM has an ultra-low power standby solution that an embedded power-FSM can perform standby events and wake up the system as required. UIS8910DM 8.9X8.9mm TFBGA package and 301 balls.
PMIC used to generate various power supply rail is UIP8910M, It’s an external DC-DC and LDOs solution(PMIC UIP8910M), in many latest modems you will find PMIC implemented inside the Main processor itself.
See the image below, along with PMIC chip, you see three large inductors and ceramic capacitors.
There are three RF chips other than SoC and PMIC.
The first one you see from the top is RPM6743-31, it is a multi channel LTE RF amplifier for RX and TX block.
RPM6743 is a multi-mode multi-band (MMMB) power amplifier module supporting CDMA, WCDMA , TD-SCDMA , TDD / FDD LTE modes. The module is fully programmable via the mipi RFFE interface. The RPM6743-31 includes three amplifier paths for low, mid and high frequency bands, followed by a switching output for multi-band coverage. The module is packaged in a 4.0 mm × 6.8 mm × 0.82 mm 42-pad MCM package.
Another RF IC used is RTM7916-51
The RTM7916-51 transceiver front-end module (FEM) supports Class 12 GPRS , EDGE multi-slot operation and TD-SCDMA / TDD -LTE linear transmission. 14 transmit/receive (TRx) ports and integrated directional coupler enable wideband 3G/4G RF switching, the module includes CMOS controller, low-band PA module supporting GSM850/900 band, high-band supporting GSM850/900 band PA module DCS1800/PCS1900, TD-SCDMA band 34/39 and TDD-LTE band 34/39, input/output matching network, Tx harmonic filtering, RF switching and directional coupler at the antenna output .
The low current PA controller includes MIPI RFFE and decoder circuitry. In GMS K mode, the PA controller provides envelope amplitude control based on VRAMP and reduces sensitivity to input drive, temperature, power supply, and process variations. Proper timing of MIPI commands and VRAMP inputs ensures a high degree of isolation between the antenna and Tx-VCO when tuning the VCO before transmitting a burst. VRAMP voltage and MIPI-based bias settings optimize PA linearity and efficiency in EDGE and TD-SCDMA/TDD-LTE linear modes.
Another RF chip used on the module is for GPS, it is UC6228CI
The UC6228CI is a low power, high performance GNSS SoC from Unicore Communications. It can receive and track GPS L1 signals at 1575.42 MHz and GLONASS L1 signals. It also supports GPS, BDS, GLONASS, and Galileo systems.
I hope you found the information useful. That’s all in this teardown.
Will be back with another blog soon, keep learning new things!
I am currently working as an embedded systems design consultant helping companies build custom embedded products and develop test automation solutions for their PCBs.
If you have any feedback about the blog, you can share it in the comments below or contact me directly.