Analog Devices has developed new power detector and power controller ICs for cellular handsets that offer high accuracy and temperature stability in tiny, 0.6 mm-thick packages.
The ADL5500 is the newest member of ADI’s TruPwr family of detectors, which are optimized to measure complex waveforms at RF frequencies and deliver an accurately scaled dc voltage that is the true RMS (root mean square) equivalent of the input waveform.
In addition to the super small package, the ADL5500 further 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 temperature stability (0.1 dB variation over the –40 degrees C to +85 degrees C range) eases the design and manufacture of cellular handsets by reducing the calibration burden.
The ADL5500 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 the ADL5500 ideal for CDMA, CDMA2000, TD-SCDMA and W-CDMA cellular handsets, as well as emerging broadband wireless standards, such as 802.16.
The AD8311 is a logarithmic power controller that provides precise control of RF power amplifiers (PA) operating in the frequency range of 100 MHz to 2.5 GHz and over a typical 45-dB dynamic range.
The 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 degrees C to +85 degrees C, and wide dynamic range make the AD8311 well suited for GSM/GPRS cellular handsets and other applications that require transmit power control.
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.