Wireless Microsite
STMicroelectronics Shrinks Next-Generation Bluetooth Designs by Connecting the Antenna Through a Single Chip
Two new ICs from STMicroelectronics allow designers to connect an antenna to a Bluetooth transceiver using a single chip, making Bluetooth-enabled products simpler, smaller and easier to build. The BAL-2593D5U and BAL-2690D3U are integrated baluns, used to convert the antenna signal to a balanced pair of signals as required by the Bluetooth transceiver. As replacements for traditional baluns built with discrete components, the new devices occupy up to 70% less printed-circuit-board area, simplify design and assembly, and ensure better balanced signal channels with low losses, thereby improving wireless performance.
The The BAL-2593D5U is optimized for use with the STLC2500D standalone Bluetooth transceiver and STLC2592/3 combo devices, which implement an FM radio tuner enabling users to listen to radio directly on a Bluetooth headset. The BAL-2690D3U is designed to partner the STLC2690, a Bluetooth /FM-tuner combo that also adds a short-range FM transmitter allowing the user to play stored music through a system such as a car radio.
Key features of ST’s integrated baluns:
BAL-2593D5U:
* 50/50+j50 Ohm impedance
* 1.16 x 1.26mm footprint; sub-0.7mm profile
* 1.2dB insertion loss
* Matches STLC2592/3, STLC2500D
BAL-2690D3U:
* 50/30+j25 Ohm impedance
* 0.91 x 0.91mm footprint; sub-0.7mm profile
* 0.8dB insertion loss
* Matches STLC2690