RF power detector extends battery life says National

The PowerWise LMH2120 has been designed to increase wireless coverage and extend battery life for 3G and 4G mobile handsets. According to National, the LMH2120 linear RMS rf power detector enables accurate rf power amplifier (PA) measurements, which are used to control transmit power and avoid interference with neighbouring signals. It provides stable performance over the temperature range of -40 to 85^°C, with a temperature variation of +/- 0.5dB over a 40dB dynamic range at 1900MHz. This feature has been designed to increase coverage and quality of service, such as higher uplink data rates at greater distance from the cell tower. The LMH2120's performance remains consistent across various modulation schemes in multi-mode handsets and data cards using CDMA, W-CDMA, UMTS, LTE, GSM and GPRS cellular standards. It provides modulation-independent measurements of < 0.3dB, which eliminates the extensive look up tables required for accuracy. It also includes a shutdown pin for reducing power consumption in between measurements to extend handset battery life. The power detector operates from a single 2.7 to 5V supply and provides an output voltage proportional to the rf input power in dBm. It features a supply current of 2.9mA and includes a low power shutdown mode which National says reduces power consumption to 3.8 uA. It supports frequencies of 50MHz to 6GHz, with an rf power detection range of -35 to 5dBm.