SST Introduces Efficient Power Amplifiers For Battery Powered WLAN Applications
Sunnyvale, CA -- SST Communications, a developer of RF integrated circuits for wireless and multimedia applications, today introduced two new high-efficiency power amplifiers for 802.11a and 802.11b/g WLAN systems. Both devices offer low power consumption, as well as on-chip power detection to provide maximum efficiency and significant cost savings to designers of power-sensitive WLAN equipment, such as PCMCIA, MiniPCI, and USB cards, and handheld computing and communications devices. Additionally, the high-efficiency power amplifiers enable customers to save on bill of material costs and PCB space -- thus reducing overall total ownership costs -- by featuring on-chip power detectors and minimizing the number of external devices.
"There is certainly a lot of momentum building throughout the wireless industry to embed WLAN connectivity in a host of new applications, namely cellular phones and other small portable communication devices," said Frank Chang, vice chairman and CTO, SST Communications. "Embedding WLAN capabilities into portable electronics places added challenges on design engineers, as they must develop new techniques for limiting power consumption. Our new high-efficiency power amplifiers provide wireless systems designers with a reliable, low-power solution that doesn't force compromises on performance or cost."
The new power amplifiers include the SST12LP14A for 2.4 GHz 802.11b/g and the SST11LP11 for 5 GHz 802.11a. When configured for high-efficiency operation, the SST12LP14A only requires a low-quiescent current (Icq) of 45 mA. It provides 29 dB gain and linear output power of 17 dBm at Icc of 85 mA. Under high-power configuration, the same device provides Pout of 22 dBm at 210 mA for 802.11g and Pout of 23 dBm at 240 mA for 802.11b application, respectively. The SST12LP14A has linearity of approximately 4% added EVM (error vector magnitude) at 22 dBm output power, which is essential for 54 Mbps 802.11g operation while meeting the standard's spectrum mask at +24 dBm.
Designed to operate over the entire 802.11a band between 4.9 and 5.8 GHz, the SST11LP11 requires Icq of 80 mA. It consumes 180 mA when delivering 24 dB gain and 18 dBm output power across the entire 4.9 to 5.8 GHz band with 4% added EVM.
The SST12LP14A power amplifier features a load-insensitive, on-chip power detector, which leads to system cost savings for customers due to eliminating the costly off-chip Schottky diode detector with on-board directional coupler. The SST12LP14A power detection ranges from 0.6 to 1.8 V to cover 0 to 23 dBm output power with dB-wise linearization and high stability over temperature (< +/- 0.3 dB over 0 to 85 degrees C), frequency (< +/- 0.3 dB across Channel 1 to 14), and output load (< +/- 0.4 dB with a 2:1 VSWR [voltage standing wave ratio] mismatch load at all angles). The SST11LP11 features on-chip power detector ranges from 0.6 to 2.0 V to cover 0 to 20 dBm output power, with < +/- 0.5 dB over -10 to +85 degrees C temperature stability.
In addition to the on-chip power detectors, the SST12LP14a and the SST11LP11 feature less than 200 nsec power up/down control through a single combined reference voltage pin. The low reference current of the devices (Iref of 2 mA for the SST12LP14A and 14 mA for the SST11LP11) allows them to be controlled by on/off switching signals directly from the baseband chip, thus resulting in further power consumption savings.
SST Communications' power amplifiers are manufactured using an InGaP/GaAs HBT technology, with tested MTTF exceeding 6x108 hours at 100 degrees C.
The SST12LP14A and the SST11LP11 are available now in production quantities. The SST12LP14A is pin compatible to the SST12LP14 and is offered in a 3 mm by 3 mm, 16-pin LCC (leadless chip carrier) package. The SST11LP11 is offered in a 3 mm by 3 mm, 16-pin VQFN (very thin quad flat no-lead) package. Both devices are also offered in non-Pb (lead free) packages.
Source: SST Communications