Overview: why communication IC choice matters
Selecting the correct communication IC (UART, SPI, I2C, CAN, Ethernet PHY, USB, or RF transceiver) is often the difference between a smooth prototype and weeks of troubleshooting. For makers, tertiary students and engineering teams in South Africa, practical concerns - local availability, lead times, branch pickup, and VAT invoices - are as important as electrical specs. This guide walks through the standards and specifications you need, real-world selection tips, and worked examples you can replicate on the bench.
Common categories of communication ICs
Communication ICs fall into a few practical groups: serial interface drivers (UART, RS-232/RS-485 transceivers), bus controllers (I2C/SPI masters and expanders), network PHYs and MAC+PHY combos (Ethernet), automotive/industrial transceivers (CAN/LIN), USB controllers, and RF transceivers (LoRa, Zigbee, sub-GHz). Each group trades off speed, distance, power and software complexity.
Where to check local stock and manufacturers
Before finalising a part number, verify availability in South Africa to avoid long lead times. Browse Communica's collections for category matches and brands to see what's typically stocked, and plan branch collection when time is tight: Shop by Category. For a broad search across the catalogue, use the all-products index: All Products. Learn about Communica's history and service model that supports education and industry on the About page: About Us.
Standards and key specifications
Focus on electrical interface levels, data rates, package and thermal limits, and regulatory needs specific to your deployment. Below is a compact spec comparison for common IC classes to guide initial selection.
| IC Type | Typical Data Rate | Voltage Levels | Distance/Application |
|---|---|---|---|
| UART/TTL Transceiver | 115.2 kbps typical (up to Mbps) | 1.8V / 3.3V / 5V | On-board serial comms, debug ports |
| RS-485/RS-232 Transceiver | 100 kbps - 10 Mbps | Differential ± drivers | Multi-drop industrial links, long cable runs |
| I2C/SPI Controllers | I2C: up to a few Mbps; SPI: tens of Mbps | 1.8V / 3.3V | Sensor buses, peripheral expansion |
| CAN Transceivers | 125 kbps - 1 Mbps | Differential (bus) 2.5-5V logic | Automotive/industrial control |
| Ethernet PHY | 10/100/1000 Mbps | 1.8V/3.3V cores | LAN connectivity, PoE-adjacent |
| Sub-GHz / LoRa / Zigbee | kbps - 100s kbps | 1.8V / 3.3V RF front-ends | Low-power wide-area, mesh networks |
Electrical rules of thumb
Match voltage domains or include level-shifters; watch for TX/RX idle states and pull-ups on open-drain buses (I2C). For long runs, choose differential transceivers (RS-485 or CAN) and terminate properly. For wireless links, reserve headroom in link budget for real-world losses and local interference sources.
Simple wiring ASCII for RS-485 half-duplex with termination
Master A -----+--------------------------------+----- Slave A
| |
+-- 120 Ohm ---(bus)--- 120 Ohm --+
Master B -----+--------------------------------+----- Slave B
Place 120 Ohm termination at each physical end of the differential pair
