AD8361 Datasheet, PDF (1/16 Pages) Analog Devices – LF to 2.5 GHz TruPwr™ Detector

a
LF to 2.5 GHz
TruPwr^™ Detector
AD8361
FEATURES
Calibrated RMS Response
Excellent Temperature Stability
Up to 30 dB Input Range at 2.5 GHz
700 mV rms, 10 dBm re 50 ⍀ 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 ␮A
APPLICATIONS
Measurement of CDMA, W-CDMA, QAM, Other
Complex Modulation Waveforms
RF Transmitter or Receiver Power Measurement
FUNCTIONAL BLOCK DIAGRAMS
micro_SOIC
RFIN
PWDN
␹^{2 i}
TRANS-
CONDUCTANCE
CELLS
␹^{2 i}
ERROR
AMP
BAND-GAP
REFERENCE
INTERNAL FILTER
AD8361
VPOS
FLTR
؋ 7.5
BUFFER
VRMS
ADD
OFFSET
SREF
COMM
IREF
PRODUCT 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 only a single supply between
2.7 V and 5.5 V, 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 averag-
ing 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 (SOT-23-6L Package Ground Reference
Mode Only)
SOT-23-6L
RFIN
␹^{2 i}
TRANS-
CONDUCTANCE
CELLS
␹^{2 i}
ERROR
AMP
INTERNAL FILTER
AD8361
؋ 7.5
BUFFER
VPOS
FLTR
VRMS
PWDN
BAND-GAP
REFERENCE
COMM
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 referenced 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 V_S/7.5.
The AD8361 is specified for operation from –40°C to +85°C and
is available in 8-lead micro_SOIC and 6-lead SOT packages.
It is fabricated on a proprietary high f_T silicon bipolar process.
TruPwr is a trademark of Analog Devices, Inc.
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
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© Analog Devices, Inc., 2000