hf/rf ZONE Products for the week of August 26, 2002
SiGe Semiconductor says . . .
SE2522L: SiGe Semiconductor Delivers Impressive Combination
of Performance and Power Consumption with 802.11b Power Amplifier
Power amp with integrated power detector complements high-performance
CMOS radios
SiGe Semiconductor announced the SE2522L, a highly linear 2.4GHz power amplifier that delivers the industry's best combination of performance and power efficiency to IEEE 802.11b systems. The device combines an efficient silicon germanium architecture with power control circuitry to reduce current consumption by as much as 50 percent compared to competitors, while achieving superior power added efficiency that ensures reliable transmissions over an extended range. SiGe's SE2522L is sampling now, and is expected to drive 802.11b-enabled laptop PCs, computer peripherals, cellular handsets, and other handheld computing devices by year end.
The SE2522L is the latest addition to SiGe Semiconductor's RangeCharger portfolio of wireless power amplifiers and front-end devices. It is based on the popular SE2520L, launched last December. Since its launch, the SE2520L has been selected by major manufacturers for 2.4GHz products, including 802.11b reference designs and cordless phones, which will be on the market later this year.
SiGe's SE2522L leverages the proven architecture of the SE2520L, adding a power detector to augment the performance and simplify design of WLAN systems based on a CMOS radio. While CMOS radios are popular for their ability to meet low cost and high integration requirements, they produce variable power out that can affect the stability of WLAN transmissions. SiGe Semiconductor eliminates the need for extra circuitry to correct this by integrating a power detector that ensures output power stability.
"Initial customer feedback of the SE2522L has been positive, and
we are confident that the device will extend our penetration into the 802.11b
market," said Bill Cuming, vice president optical, cable and components,
SiGe Semiconductor. "When choosing from the range of power amplifiers
available on the market, customers no longer have to sacrifice current consumption
for performance. The SE2522L solves all of these requirements as an efficient,
easy to implement solution."
analogZONE Says . . .
The SE2520L was launched by SiGe Semiconductor at the end of 2001. It was/is a neat product but it missed on the important conversion market -- persuading designers to take their CMOS solutions out to drop in a SiGe one. That is changed here in the SE2522L with the addition of an output power detector which will allow for simple AGC of the output power level back to a control pin, where the complete range of output power can be adjusted with voltages from 0.1 V to 1.6 V.
The range of the power detector is 17 dB -- with an accuracy of +/-1.0 dB -- from 6 dBm to 23 dBm. The IC is designed for 3.3-V operation with a saturated input (+2 dBm) quiescent of 140 mA typical or 110 mA in linear operation, considerably less than I have seen from other solutions. A digital enable control is provided with on/off ramping of typically 1 us. The two active amplifier stages are ac coupled.
Designed, of course, for the range of 2400 MHz to 2485 MHz, the SE2522L offers a WLAN output of 20 dBm with an input power of -7 dBm (i.e. 27 dB of small signal gain) and an ACPR of -30 dBc. Power can be throttled back to as little as -5 dBc. 2nd, 3rd, 4th and 5th harmonics are all better than -50 dBc (i.e. better than -70 dB at full linear output) with 42 dB of reverse isolation (S12.) For cordless phone applications the output can be wound up to +23 dBm saturated power with a 3.6-V supply. No numbers are quoted for S11 and S22 in the preliminary information although it is hinted at in the specifications that both input and output require external matching networks, with different networks required for linear and saturated operation.
This Canadian company is steadily, and professionally, building itself into a mainstream supplier and has gained a lot of attention from OEMs looking for elegant solutions -- and deservedly so: They are delivering on their promises in a market that is not always so conscious of that need, and they have a reputation to be proud of for such a young operation.
The SE2522L is sampling now in a LPCC-8 and it will also be made available
in chip-scale later. It is being priced at $0.94 in 100-k piece lots.