Single-chip balun integrated into sensor-enabled RF modules

June 17, 2014 // By Graham Prophet
A tiny single-chip balun, together with ST’s MEMS sensor and EEPROM, helps boost performance and shrink dimensions of AiroSensor and AssetSensor active-RFID modules from SenseAnywhere. The BAL-CC1101-01D3 is first in a family of single-chip baluns optimisded for specific RF transceiver chipsets

SenseAnywhere, maker of tags and modules for wireless sensing and location, has qualified the first wireless devices incorporating ST's new single-chip balun, which integrates essential circuitry for radio systems in a footprint of only 2.1 mm 2.

The SenseAnywhere AiroSensor and AssetSensor active-RFID modules combine RF transceiver technology with a low-power processor, low-voltage EEPROM, and miniature temperature, humidity, and ultra-efficient motion sensors to enhance performance and save cost in Internet of Things (IoT) applications such as environmental monitoring, cold-chain compliance, theft protection, and asset tracking.

Inside the SenseAnywhere modules, ST’s BAL-CC1101-01D3 balun (balanced-to-unbalanced transformer) balances the connection between the radio and antenna, replacing discrete components that would occupy up to 30 mm 2 of pc-board space with a single 2.1 mm 2 integrated circuit. Single-chip integration enables closer impedance matching, greater stability, and reduced device-to-device spread by minimising variations between circuit features on the same silicon substrate.

“The cooperation with ST made it possible to realise significant improvements in the output performance, sensitivity and impedance matching of our RF modules and sensors, as well as minimising unwanted harmonics,” said Tom Heijnen, Founder and Managing Director of SenseAnywhere. “At the same time, we have reduced overall application size as well as savings in bill-of-materials costs and reduced assembly and test costs.”

BAL-CC1101-01D3 is the first in a family of integrated baluns from ST, which are matched to specific RF-transceiver chipsets. Optimised for ultra-low-power applications in sub-GHz Industrial, Scientific and Medical (ISM), and Short-Range Device (SRD) frequency bands, the ETSI- and FCC-compliant BAL-CC1101-01D3 delivers advantages including an integrated harmonic filter delivering improved harmonic attenuation, low insertion loss, and operation up to 85°C.

Beyond the new balun, ST contributed its compact, flexible, and lowest-power LIS2DH accelerometer, and low-power EEPROMs to the SenseAnywhere IoT modules.

The BAL-CC1101-01D3 in the 2.1 mm 2 flip-chip package, costs from $0.26 (5000).

SenseAnywhere develops and markets wireless transceiver modules, sensor-enabled active RFID tags, wireless sensors and data