AD8361ART Datasheet, PDF (1/24 Pages) Analog Devices – LF to 2.5 GHz TruPwr Detector

FEATURES
Calibrated rms response
Excellent temperature stability
Up to 30 dB input range at 2.5 GHz
700 mV rms, 10 dBm, re 50 Ω maximum input
±0.25 dB linear response up to 2.5 GHz
Single-supply operation: 2.7 V to 5.5 V
Low power: 3.3 mW at 3 V supply
Rapid power-down to less than 1 µA
APPLICATIONS
Measurement of CDMA, W-CDMA, QAM, other complex
modulation waveforms
RF transmitter or receiver power measurement
GENERAL DESCRIPTION
The AD8361 is a mean-responding power detector for use in
high frequency receiver and transmitter signal chains, up to
2.5 GHz. It is very easy to apply. It requires a single supply only
between 2.7 V and 5.5 V, a power supply decoupling capacitor,
and an input coupling capacitor in most applications. The
output is a linear-responding dc voltage with a conversion gain
of 7.5 V/V rms. An external filter capacitor can be added to
increase the averaging time constant.
3.0
2.8
SUPPLY
2.6
REFERENCE MODE
2.4
2.2
INTERNAL
2.0 _{REFERENCE MODE}
1.8
1.6
1.4
1.2
GROUND
REFERENCE MODE
1.0
0.8
0.6
0.4
0.2
0.0
0
0.1
0.2
0.3
0.4
0.5
RFIN (V rms)
Figure 1. Output in the Three Reference Modes, Supply 3 V, Frequency 1.9 GHz
(6-Lead SOT-23 Package Ground Reference Mode Only)
LF to 2.5 GHz
TruPwr™ Detector
AD8361
FUNCTIONAL BLOCK DIAGRAMS
RFIN
PWDN
χ^{2 i}
TRANS-
CONDUCTANCE
CELLS
χ^{2 i}
BAND-GAP
REFERENCE
ERROR
AMP
INTERNAL FILTER
AD8361
× 7.5
BUFFER
ADD
OFFSET
VPOS
FLTR
VRMS
SREF
COMM
IREF
Figure 2. 8-Lead MSOP
RFIN
χ^{2 i}
TRANS-
CONDUCTANCE
CELLS
χ^{2 i}
INTERNAL FILTER
ERROR
AMP
AD8361
× 7.5
BUFFER
VPOS
FLTR
VRMS
PWDN
BAND-GAP
REFERENCE
COMM
IREF
Figure 3. 6-Lead SOT-23
The AD8361 is intended for true power measurement of simple
and complex waveforms. The device is particularly useful for
measuring high crest-factor (high peak-to-rms ratio) signals,
such as CDMA and W-CDMA.
The AD8361 has three operating modes to accommodate a
variety of analog-to-digital converter requirements:
1. Ground reference mode, in which the origin is zero.
2. Internal reference mode, which offsets the output 350 mV
above ground.
3. Supply reference mode, which offsets the output to VS/7.5.
The AD8361 is specified for operation from −40°C to +85°C
and is available in 8-lead MSOP and 6-lead SOT-23 packages. It
is fabricated on a proprietary high fT silicon bipolar process.
Rev. C
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