Solid-state relays enable self-powered control in IoT applications

August 24, 2016 // By Graham Prophet
Semtech’s (Camarillo, CA) TS13102 and TS13103 solid state relays in the Neo-Iso product range have added features to aid design of energy-harvesting and self-powered control systems in Internet of Things (IoT) applications, such as smart thermostats, alarm panels, factory automation systems, and smart controls.

The TS13102 solid state relay can autonomously harvest energy even when its switch is closed and without the assistance of a microcontroller. The harvested energy is stored in a system capacitor (Csys) and can be shared across multiple channels in the system driving several loads simultaneously.

The TS13103 is outfitted with a Power Transfer Output pin (PTO) to transfer the harvested energy on the other side of the isolation barrier to the controller of the system. This design allows for much smaller systems that can last decades without needing battery replacement. It also eliminates the need to include costly transformers and AC/DC power supplies with the system, which significantly reduces the bill of materials (BOM) cost.

Both TS13102 and TS13103 relays have an enhanced communication scheme that allows the controller to send specific commands through the control line (CLK) to perform a variety of functions, including receiving diagnostic information. The control and feedback lines can be shared across multiple channels, reducing the system microcontroller pin count. These latest additions to Semtech’s Neo-Iso product portfolio offer designers the benefit of significant board space savings and BOM cost savings compared to mechanical relays, as well as silent operation, diagnostic capability and a major increase in the lifetime of the product.