Semitech provides semiconductor devices that enable the transformation of the electricity grid into a smart grid. Specialzing in narrowband powerline communication, our chips help to transform existing infrastructures into its “smart” counterparts, reacting to conditions on the grid and implementing a worldwide communications network based on the existing power grid.
Power line communications (PLC) is a term describing different systems for using electric power lines to carry information. All power line communications systems operate by impressing a modulated carrier signal on the power wires. Different types of power line communications may use different frequency bands, depending on regulations and the system characteristics. Since the power wiring system was originally intended for transmission of AC (or DC) power, it has limited ability to propagate higher frequencies. Data rates over a PLC system vary widely. Higher data rates generally imply shorter ranges, such that a local area network operating at megabits per second may only cover several meters.
Narrowband PLC (NB PLC) is a generic term for PLC that typically operates in frequencies below 500KHz. Specifically, frequencies below 148.5KHz have been authorized by Europe’s CENELEC for broadly deployable PLC systems. Within this range high-voltage transmission lines may carry data to distances ranging from hundreds of meters to a few kilometers. The resulting data rates are modest, ranging from 1Kbps to 200Kbps. These rates are appropriate for telemetry, data gathering and control applications.
The most broadly deployed Narrowband PLC solutions employ relatively simple, but extremely cost effective FSK and B-PSK modulation techniques. Several interoperable standards have been developed based on these techniques including EIA709.2 and PLC4TRUCKS. With the advancement of communication technology, more advanced modulation techniques have developed and are being deployed. Most notably Orthogonal Frequency Division Multiplexing (OFDM) has proven to be particularly effective due to its inherent ability to adjust to the noise environment, resulting in a more robust more capable communication network. OFDM forms the basis of more recent standards such as G3-PLC, PRIME and IEEE1901.2. Semitech has devices that support each and all of these standards.