Teardown of A7672S SICOM Cellular Modem was motivated by curiosity to understand the internals of a cellular modem.
GSM (Global System for Mobile Communications) GPRS (General Packet Radio Service) modems are essential devices in wireless communication, enabling data transmission over mobile networks.
They operate on the GSM network, the most widely used cellular technology worldwide, supporting a range of frequencies like 850, 900, 1800, and 1900 MHz. GPRS, an enhancement of GSM, offers moderate-speed data transfer, suitable for applications like remote monitoring, SMS messaging, and basic internet access.
These modems are highly valued in IoT (Internet of Things) and M2M (Machine to Machine) communications for their reliability and broad network coverage. Additionally, GSM GPRS modems are known for their compatibility with a wide range of devices and networks, making them versatile for global deployment.
When I started building GSM GPRS based IoT products in 2007-2008 timeframe, SIMCOM was very popular and I remember I used SIMCOM 300 at that time in a lot of our projects.
Today also besides Quectel, SIMCOM modems are quite popular and provides cellular modems with varity of features.
This is a short blog where I wanted to share inside of SIMCOM AS7672A Cellular Modem.
SIMCOM A7672S is built on Cat.1 Multi-mode IoT Chip, ASR1603 which is manufactured in 22nm process is a high cost-effective, ultra-low-power multi-mode cellular chip.
Compared with its predecessor, ASR1603 reduces area by 14% and power consumption by 20%~25%, and enriches peripheral interfaces.
The chip can be widely used in various standard data modules and has outstanding performance in markets such as Tracker, Shared Devices, Power Grid, V2X, and various intelligent hardware.
It has RF transceiver for 450MHz to 2.7GHz bandwidth, RAM and Flash Integrated. It supports VoLTE and runs on Threadx Operating System, It has low power consumption, example: VoLTE call consumes 70mA and a GSM call consumes 50mA.
Along with ASR1603, this modem has ASR5801, which is a Bluetooth SOC (system on a chip) that supports classic BT(BR/EDR) and BLE(1M/2M/LR) v5.0.
There are two SMMI Chipsets SMMI S2916-51 and SMMI S5643-51 which are basically RF Switch and Power amplifiers for GSM/GPRS/2G/3G/4G and GPS interface.
What else is there on the module, well there are a lot of multi-rail DC DC power supplies are there, which are used for various circuitry on board.
There are other module which uses this ASR1603 chipset like:
- Quectel EG915N
- Quectel EC200N
- LB-Link BL-M1603DL1 4G
- Fn-Link P103N-U
I hope you found this teardown useful and learned something new today.
I am currently working as an embedded systems design consultant helping companies build custom embedded products and develop test automation solutions for their PCBs.
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