Solid state relays enable self-powered control systems in IoT

August 24, 2016 // By Graham Prophet
Semtech’s 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.

Semtech adds, “By eliminating the need for an additional power supply for the microcontroller, the TS13102 and TS13103 solid state relays give designers energy harvesting capability in a space saving package that can be easily integrated into a wide range of IoT applications.”

 

Features of the TS13102 & TS13103 include;

· Energy harvesting from the load with integrated bridge diodes

· Automatic, dithering-enabled energy harvesting while the switch is closed

· Enhanced diagnostic feedback with status, fault information and voltage detection

· Three address pins allowing for up to eight switches on the same control line (CLK)

· Programmable watch dog pin (WD) to safely disconnect the load after CLK