RF Power Controller Trims Calibration Times

Housed in a 1-mm tall ThinSOT package, the tiny, accurate LTC4400-1 and LTC4401-1 RF power controllers are earmarked for use in 800-MHz-to-2.7-GHz dual-band GSM systems. Compared to competitive devices, the new ICs are said to occupy less pc board real estate and reduce calibration time and DSP firmware programming by automatically canceling initial offsets and temperature-dependent offset errors. The RF detector and controller devices also have a 45 dB dynamic range, operate directly from a single Li-Ion cell, and support a wide range of RF power amplifiers from various manufacturers. Their operating voltage range extends from 2.7V to 6V and their operating current is a mere 1 mA, dropping to less than 1 µA in shutdown. Built-in circuitry protects the ICs against over-voltage conditions. The LTC4400-1 has a 450-kHz loop bandwidth and targets "fast" RF power amplifiers, while the LTC4401-1 has a 250-kHz loop bandwidth and works best with "slow" power amps. Price: $1.20 each/1,000. For more details, contact Afshin Odabaee at LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.