- Buyers Guide
SiGe Introduces High Power WLAN PA
SiGe Semiconductor Inc. has launched the SE2576L, a 2.4 GHz Wireless LAN power amplifier (PA) module. The new IEEE 802.11bgn device is the industry's smallest and most efficient power amplifier operating at 26 dBm. The SE2576L targets applications requiring high RF transmit power such as residential video and data transport, enterprise and outdoor networks as well as public hotspots, delivering complete area coverage and improved link budgets for more effective broadband data services.
Commenting on the new device, Jose Harrison, Director, Product Marketing, Computing, Networking and Consumer WLAN at SiGe, said, “We designed the SE2576L with a focus on ease-of-use and maximum flexibility. This PA module allows our customers to lower their development, qualification and certification costs. Most importantly, it assists them in reducing time to market for incorporating WiFi™ functionality into a range of previously un-networked products.”
The challenge facing high-power WLAN connectivity resides with the RF power amplifier. As the PA operates for a period of time at higher RF power levels, the PA itself tends to increase in temperature. As the PA increases in temperature, its ability to maintain the desired RF power level degrades. This in turn causes the PA control loop to increase RF power, which results in further increases to the operating temperature of the PA. In addition to reducing RF power, increased PA temperature degrades linearity performance, corrupting the transmitted data as well as creating interference in nearby WiFi™ frequency channels.
The SE2576L is fabricated in silicon germanium, a technology nearly identical to standard silicon and three times more thermally conductive than GaAs. The SE2576L integrates the input match and the external output match to adjust the load line for 5 V, 26 dBm operation enabling simplified design, enabling quicker time to market and higher production yield for SiGe’s customers.
The SE 2576 features a temperature compensated, load insensitive power detector with 20 dB of dynamic range and < 1.2 dB variation under 3:1 mismatch at the antenna. The combination of this power detector and the inherent thermal dissipation benefits of silicon germanium equips the SE2576L to deliver consistent performance over temperature extremes in high power applications where self-heating requires special attention. The new WLAN PA also features a digital enable control, featuring an integrated reference voltage generator enabling a typical 0.5 μs power ramp rise/fall time.
The 26 dBm SE2576L shares its footprint and application board design with the SE2598 (21 dBm) and the SE2565 (23 dBm), creating a three-product 2.4 GHz high-power portfolio. By changing only the component values in the tuning and matching circuit, the customer can reuse a single circuit board design for a wide range of WLAN connectivity products.
The SE2576L comes in a small lead and halogen free, ROHS-compliant, 16 pin, 3 x 3 x 0.9 mm QFN package. This low profile package height makes it suitable for easy integration in WLAN modules.