Accurate rms-to-dc conversion from 50 MHz to 9 GHz
Single-ended input dynamic range of 65 dB
No balun or external input matching required
Waveform and modulation independent, such as
Linear-in-decibels output, scaled 53 mV/dB
Transfer function ripple: <±0.1 dB
Temperature stability: <±0.3 dB
All functions temperature and supply stable
Operates from 4.5 V to 5.5 V from −40°C to +125°C
Power-down capability to 1.5 mW
Pin-compatible with the 50 dB dynamic range AD8363
Power amplifier linearization/control loops
Transmitter power controls
Transmitter signal strength indication (TSSI)
The ADL5902 is a true rms responding power detector that has
a 65 dB measurement range when driven with a single-ended
50 Ω source. This feature makes the ADL5902 frequency
versatile by eliminating the need for a balun or any other form
of external input tuning for operation up to 9 GHz.
The ADL5902 provides a solution in a variety of high frequency
systems requiring an accurate measurement of signal power.
Requiring only a single supply of 5 V and a few capacitors, it is
easy to use and capable of being driven single-ended or with a
balun for differential input drive. The ADL5902 can operate
from 50 MHz to 9 GHz and can accept inputs from −62 dBm to
at least +3 dBm with large crest factors, such as GSM, CDMA,
W-CDMA, TD-SCDMA, WiMAX, and LTE modulated signals.
The ADL5902 can determine the true power of a high
frequency signal having a complex low frequency modulation
envelope or can be used as a simple low frequency rms
voltmeter. Used as a power measurement device, VOUT is
connected to VSET. The output is then proportional to the
50 MHz to 9 GHz
65 dB TruPwr Detector
FUNCTIONAL BLOCK DIAGRAM
BIAS AND POWER- VREF
DOWN CONTROL 2.3V
logarithm of the rms value of the input. In other words, the
reading is presented directly in decibels and is scaled 1.06 V per
decade, or 53 mV/dB; 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
set point. The output buffer can provide high load currents.
The ADL5902 has 1.5 mW power consumption when powered
down by a logic high applied to the PWDN pin. It powers up
within approximately 5 μs to its nominal operating current of
73 mA at 25°C. The ADL5902 is supplied in a 4 mm × 4 mm,
16-lead LFCSP for operation over the wide temperature range
of −40°C to +125°C.
The ADL5902 is also pin-compatible with the AD8363, 50 dB
dynamic range TruPwr™ detector. This feature allows the
designer to create one circuit layout for projects requiring
different dynamic ranges. A fully populated RoHS-compliant
evaluation board is available.
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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