Rev 15 Nov 2013 12:50 | Page 3
The CN0178 circuit uses the ADL5902 TruPwr™ detector to measure the rms signal strength of RF
signals with varying crest factors (peak-to-average ratio) over a dynamic range of approximately 65
dB and operates at frequencies from 50 MHz up to 9 GHz.
The measurement result is provided as serial data at the output of a 12-bit ADC (AD7466).
The ADL5902 is a true rms responding power detector that has a 65 dB measurement range when
driven with a single-ended 50 O source. This feature makes the ADL5902 frequency versatile by
eliminating the need for a balun or any other form of external input tuning for operation up to 9 GHz.
The ADL5902 provides a solution in a variety of high frequency systems requiring an accurate
measurement of signal power. Requiring only a single supply of 5 V and a few capacitors, it is easy to
use and capable of being driven single-ended or with a balun for differential input drive. The ADL5902
can operate from 50 MHz to 9 GHz and can accept inputs from -62 dBm to at least +3 dBm with large
crest factors, such as GSM, CDMA, W-CDMA, TD-SCDMA, WiMAX, and LTE modulated signals.
The AD7466 is 12-bit, high speed, low power, successive approximation analog-to-digital converter
(ADC). The part operates from a single 1.6 V to 3.6 V power supply and feature throughput rates up to
200 kSPS with low power dissipation. The part contains a low noise, wide bandwidth track-and-hold
amplifier, which can handle input frequencies in excess of 3 MHz.
The EVAL-CN0178-SDP board contains the circuit to be evaluated, as described in this note. To
power the EVAL-CN0178C-SDP evaluation board supply +6V between the +6 V and GND inputs.
More information
CN0178 Info - circuit note information
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ADL5902 Product Info - pricing, samples, datasheet
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AD7466 Product Info - pricing, samples, datasheet
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EVAL-CN0178-SDP evaluation board user guide
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Xilinx KC705 FPGA board
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