Description

The AD8364 is a true rms, responding, dual-channel RF powermeasurement subsystem for the precise measurement and controlof signal power. The flexibility of the AD8364 allows communicationssystems, such as RF power amplifiers and radio transceiverAGC circuits, to be monitored and controlled with ease. Operatingon a single 5 V supply, each channel is fully specified for operationup to 2.7 GHz over a dynamic range of 60 dB. The AD8364provides accurately scaled, independent, rms outputs of both RFmeasurement channels. Difference output ports, which measurethe difference between the two channels, are also available. Theon-chip channel matching makes the rms channel differenceoutputs extremely stable with temperature and process variations.The device also includes a useful temperature sensor with anaccurately scaled voltage proportional to temperature, specifiedover the device operating temperature range. The AD8364 canbe used with input signals having rms values from −55 dBm to+5 dBm referred to 50 Ω and large crest factors with noaccuracy degradation. Integrated in the AD8364 are two matched AD8362 channels(see the AD8362 data sheet for more information) with improvedtemperature performance and reduced log conformance ripple.Enhancements include improved temperature performance andreduced log-conformance ripple compared to the AD8362. On-chipwide bandwidth output operational amplifiers are connectedto accom-modate flexible configurations that support manysystem solutions.The device can easily be configured to provide four rmsmeasurements simultaneously. Linear-in-dB rms measurementsare supplied at OUTA and OUTB, with conveniently scaledslopes of 50 mV/dB. The rms difference between OUTA andOUTB is available as differential or single-ended signals atOUTP and OUTN. An optional voltage applied to VLVLprovides a common mode reference level to offset OUTP andOUTN above ground.The AD8364 is supplied in a 32-lead, 5 mm × 5 mm LFCSP, forthe operating temperature of –40°C to +85°C.Applications Wireless infrastructure power amplifier linearization/control Antenna VSWR monitor Gain and power control and measurement Transmitter signal strength indication (TSSI) Dual-channel wireless infrastructure radios