Minimizing RF circuit design challenges for size- and cost-sensitive applications.

STMicroelectronics has launched a balun optimized for its 868-927MHz low-power wireless transceiver, the S2-LP.

This solution enables engineers to minimize RF circuit design challenges and reduce board space in size- and cost-sensitive applications such as IoT sensors, smart meters, alarms, remotes, building automation, and industrial control.

The newly released BALF-SPI2-01D3, measuring 3.26 mm2, integrates all the impedance-matching and filtering components required to connect an antenna to the S2-LP wireless transceiver. It replaces a conventional network of 16 discrete capacitors and inductors, which can occupy up to 100 mm2 of board space, reducing the board footprint by more than 90%.

In addition to saving space, circuit design is significantly simplified by eliminating the need for component value selection or precise layout. Optimized for the S2-LP, the product comes with tested and verified placement and connection recommendations, enabling immediate iterative verification to maximize RF performance.

The BALF-SPI2-01D3 is a new member of ST's integrated balun family. The family comprises 16 devices with package sizes as small as 0.8mm2 and a height of just 0.56mm after soldering, and can be used with ST's sub-1GHz or Bluetooth low energy (Bluetooth LE) 2.4GHz radios, as well as a variety of transceivers from other manufacturers.

A key technology enabling these highly integrated matching devices is ST's Integrated Passive Device (IPD), which is implemented on a non-conductive glass substrate to minimize RF signal loss due to low amplitude and phase imbalance. Ultimately, this significantly improves RF subsystem performance and extends the operating life of battery products.

Connected smart devices are becoming increasingly important for supporting consumer lifestyles and enhancing business efficiency and new service innovations in commercial, energy, and industrial sectors. In this rapidly growing market, designers can leverage ST's integrated baluns to gain a competitive edge by reducing product size, maximizing performance, and accelerating development cycles.