The AD8364 is a true rms, responding, dual-channel RF power
measurement subsystem for the precise measurement and control
of signal power. The flexibility of the AD8364 allows communications
systems, such as RF power amplifiers and radio transceiver
AGC circuits, to be monitored and controlled with ease. Operating
on a single 5 V supply, each channel is fully specified for operation
up to 2.7 GHz over a dynamic range of 60 dB. The AD8364
provides accurately scaled, independent, rms outputs of both RF
measurement channels. Difference output ports, which measure
the difference between the two channels, are also available. The
on-chip channel matching makes the rms channel difference
outputs extremely stable with temperature and process variations.
The device also includes a useful temperature sensor with an
accurately scaled voltage proportional to temperature, specified
over the device operating temperature range. The AD8364 can
be used with input signals having rms values from −55 dBm to
+5 dBm referred to 50 Ω and large crest factors with no
accuracy degradation.
Integrated in the AD8364 are two matched AD8362 channels
(see the AD8362 data sheet for more information) with improved
temperature performance and reduced log conformance ripple.
Enhancements include improved temperature performance and
reduced log-conformance ripple compared to the AD8362. On-chip
wide bandwidth output operational amplifiers are connected
to accom-modate flexible configurations that support many
system solutions.
The device can easily be configured to provide four rms
measurements simultaneously. Linear-in-dB rms measurements
are supplied at OUTA and OUTB, with conveniently scaled
slopes of 50 mV/dB. The rms difference between OUTA and
OUTB is available as differential or single-ended signals at
OUTP and OUTN. An optional voltage applied to VLVL
provides a common mode reference level to offset OUTP and
OUTN above ground.
The AD8364 is supplied in a 32-lead, 5 mm × 5 mm LFCSP, for
the 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
