Analog Devices Inc. has developed new power detector and power controller ICs that offer high accuracy and temperature stability in tiny, 0.6 mm-thick packages. The power detectors and controllers use precision circuit design to accurately measure and control transmitter output signals independent of temperature variations, helping to reduce power consumption and making them essential components in cellular handsets.

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The ADL5500 RMS power detector is optimized for CDMA, CDMA2000 (including 1xEV-DO), TD-SCDMA, and W-CDMA cellular handsets, as well as for terminal devices for 802.16, WiMAX, and emerging wireless systems with high-crest-factor waveforms. According to ADI, the ADL5500 is up to five times more accurate, offers up to 10 times better temperature stability and, with its ultra-small, 1 mm x 1 mm package, reduces the board space requirement by more than one-half compared to competitive products.

Likewise, the AD8311 power controller is designed for GSM/GPRS cellular handsets. Housed in a tiny 1 mm x 1.5 mm package, it is the industry's smallest power controller, delivering twice the accuracy and temperature stability, while occupying one-third less board space than competitive solutions, according to Analog Devices.

The ADL5500 is the newest member of its TruPwr family of detectors, which are optimized to measure complex waveforms at RF and deliver an accurately scaled DC voltage that is the true RMS (root mean square) equivalent of the input waveform. In addition, it reduces board area with on-chip integration of an AC coupling capacitor, a 50-Ohm matching resistor and a filter capacitor. The device's high level of accuracy (±0.25 dB linear response up to 2.5 GHz) and excellent temperature stability (0.1 dB variation over the -40°C to +85°C range) eases the design and manufacture of cellular handsets by reducing the calibration burden. It requires a single supply between 2.7 V and 5.5 V and consumes only 3.3 mW at 3 V. The ability to measure 100 MHz to 6 GHz signals with varying crest factors makes ADL5500 suitable for CDMA, CDMA2000, TD-SCDMA and W-CDMA cellular handsets, as well as emerging broadband wireless standards, such as 802.16.

Likewise, the AD8311 is a logarithmic power controller that provides precise control of RF power amplifiers operating in the frequency range of 100 MHz to 2.5 GHz and over a typical 45-dB dynamic range. The high sensitivity of the AD8311 allows measurement at low power levels, thus reducing the amount of power being coupled to the detector. The device also offers low power consumption of only 8.5 mA from a 2.7 V to 5.5 V supply. The small size, high accuracy, excellent temperature stability over the range of -40°C to +85°C, and wide dynamic range make the AD8311 well suited for GSM/GPRS cellular handsets and other applications that require transmit power control, said ADI.

The ADL5500 is sampling now, with production quantities scheduled for July 2005, and is priced at 90 cents per unit in 10,000-piece quantities. The AD8311 is available now and is priced at $1.20 per unit in 10,000-piece quantities.