Targeting applications such as smart phones, netbooks, personal media players, and digital cameras, SiGe Semiconductor’s SE2601T RF switch/low-noise amplifier (LNA) front-end IC is designed to enhance the performance and functionality of converged Bluetooth/Wi-Fi chipsets that already have a built-in CMOS power amplifier (PA).

The chip is an integrated front-end with a Bluetooth port to complement wireless local-area network (WLAN) chip sets with an integrated PA. It consists of a single-pole triple-throw (SP3T) switch and an LNA with 12 dB of gain and a noise figure of 1.8 dB. The total path loss for Bluetooth is only 0.7 dB.

The SE2601T improves the connectivity range of the Wi-Fi solution by placing a high-performance LNA between the antenna and the RF receiver that’s part of chipsets from leading vendors such as CSR, Marvell, Broadcom, and Atheros. The LNA function often is omitted in embedded applications such as smart phones due to physical space constraints on the Wi-Fi solution, degrading connectivity performance. This LNA significantly increases the sensitivity of the Wi-Fi receiving system, which is critical in embedded applications where physically small antennas are limited in their contribution to signal quality.

The RF switch function that supports antenna sharing between Bluetooth and 802.11b/g/n functions is typically a discrete device requiring additional passives and consuming more space than the SE2601T solution. Thus, the SE2601T significantly decreases the footprint required for enhancing Wi-Fi performance while supporting a shared antenna for Bluetooth and Wi-Fi.

The SE2601T also integrates the required dc blocking capacitors through the use of a silicon-based IC process. Comparable GaAs-based (gallium arsenide) devices generally require external capacitors, consuming additional circuit board space and causing an incremental increase in bill-of-materials cost for the Wi-Fi solution.

The chip comes in a small lead- and halogen-free, 2- by 2- by 0.6-mm quad flat no-lead (QFN) package that complies with the European Union’s Restrictions on Hazardous Substances (RoHS). The SE2600S chip-scale package version is designed for Wi-Fi module makers. The SE2601T costs $0.35 in quantities of 10,000 units. Sampling now, it’s offered with product and evaluation board datasheets and extensive application notes detailing the use of the device.

SiGe Semiconductor Inc.