RMS power detector for RF communications designs spans 10 GHz

March 25, 2013 // By Graham Prophet
Analog Devices' latest RMS power detector features operation up to 10 GHz and a 67 dB measurement range: the ADL5906 TruPwr RMS detector is frequency-versatile and eliminates the need for external input tuning devices, such as a balun (balanced-to-unbalanced signal line transformer).

ADI designed the ADL5906 for applications that require an accurate RMS measurement of signal power including communications infrastructure, power amplifier linearisation, point-to-point and point-to-multipoint, cable, military, satellite, instrumentation equipment and ISM band transmitters.

Requiring only a single supply of 5V and a few capacitors, the detector is easy-to-use and capable of being driven with a single-ended or differential input drive. It provides low temperature drift across a -55ºC to +125ºC that is highly repeatable from part-to-part, thereby reducing design risk and manufacturing costs.

The device is specified to deliver accurate RMS-to-dc conversion from 10 MHz to 10 GHz; has a single-ended ± 1dB detection range of 67 dB at 2140 MHz, with no balun or external input matching required; and it is tolerant of high peak/average ratio and varying crest factors with response-independent acceptance of waveform types such as GSM/CDMA/W-CDMA/TD-SCDMA/WiMAX/LTE. It will accept inputs from -65 dBm to +8 dBm.

The device yields a linear-in-decibels output (that is it has in-built linear to logarithmic conversion), scaled 55 mV/dB (1.1V per decade) at 2140 MHz; has temperature stability of < ±1 dB from -40°C to +85°C; powers-down to 250 µA; and is pin-compatible with the ADL5902 and AD8363 TruPwr detectors. It comes in a 4mm x 4mm 16-lead LFCSP package and costs $5.59 (1000).

More at www.analog.com/adl5906