50 Hz to 6 GHz,
50 dB TruPwr™ Detector
AD8363
FEATURES
Accurate rms-to-dc conversion from 50 Hz to 6 GHz
Single-ended input dynamic range of >50 dB
No balun or external input tuning required
Waveform and modulation independent, such as
GSM/CDMA/W-CDMA/TD-SCDMA/WiMAX/LTE
Linear-in-decibels output, scaled: 52 mV/dB
Log conformance error: <±0.15 dB
Temperature stability: <±0.5 dB
Voltage supply range: 4.5 V to 5.5 V
Operating temperature range: −40°C to +125°C
Power-down capability to 1.5 mW
Small footprint, 4 mm × 4 mm, LFCSP
FUNCTIONAL BLOCK DIAGRAM
VTGT
12
VREF
11
VPOS
10
COMM
9
NC
13
AD8363
8
TEMP
X
2
INHI
14
X
2
INLO
15
6
7
VSET
VOUT
TCM1
16
5
CLPF
07368-001
APPLICATIONS
Power amplifier linearization/control loops
Transmitter power controls
Transmitter signal strength indication (TSSI)
RF instrumentation
1
2
3
4
TCM2/PWDN
CHPF
VPOS
COMM
Figure 1.
GENERAL DESCRIPTION
The AD8363 is a true rms responding power detector that can
be directly driven with a single-ended 50 Ω source. This feature
makes the AD8363 frequency versatile by eliminating the need
for a balun or any other form of external input tuning for operation
up to 6 GHz.
The AD8363 provides an accurate power measurement,
independent of waveform, for a variety of high frequency
communication and instrumentation systems. Requiring only
a single supply of 5 V and a few capacitors, it is easy to use and
provides high measurement accuracy. The AD8363 can operate
from arbitrarily low frequencies to 6 GHz and can accept inputs
that have rms values from less than −50 dBm to at least 0 dBm,
with large crest factors exceeding the requirements for accurate
measurement of WiMAX, CDMA, W-CDMA, TD-SCDMA,
multicarrier GSM, and LTE signals.
The AD8363 can determine the true power of a high frequency
signal having a complex low frequency modulation envelope, or
it can be used as a simple low frequency rms voltmeter. The high-
pass corner generated by its internal offset-nulling loop can be
lowered by a capacitor added on the CHPF pin.
Used as a power measurement device, VOUT is connected to
VSET. The output is then proportional to the logarithm of the
rms value of the input. The reading is presented directly in
decibels and is conveniently scaled to 52 mV/dB, or approximately
1 V per decade; however, other slopes are easily arranged. In
controller mode, the voltage applied to VSET determines the
power level required at the input to null the deviation from the
setpoint. The output buffer can provide high load currents.
The AD8363 has 1.5 mW power consumption when powered
down by a logic high applied to the TCM2/PWDN pin. It powers
up within about 30 μs to its nominal operating current of 60 mA at
25°C. The AD8363 is available in a 4 mm × 4 mm 16-lead LFCSP
for operation over the −40°C to +125°C temperature range.
A fully populated RoHS-compliant evaluation board is also
available.
Rev. 0
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responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
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