The ADL5504 is a TruPwr™ mean-responding (true rms) power detector for use in high frequency receiver and transmitter signal chains from 450 MHz to 6000 MHz. Requiring only a single supply between 2.5 V and 3.3 V, the detector draws less than 1.8 mA. The input is internally ac-coupled and has a nominal input impedance of 500 Ω. The rms output is a linear-responding dc voltage with a conversion gain of 1.87 V/V rms at 900 MHz.
The ADL5504 is a highly accurate, easy to use means of determining the rms of complex waveforms. It can be used for power measurements of both simple and complex waveforms but is particularly useful for measuring high crest factor (high peak-to-rms ratio) signals, such as W-CDMA, CDMA2000, WiMAX, WLAN, and LTE waveforms.
The on-chip modulation filter provides adequate averaging for most waveforms. For more complex waveforms, an external capacitor at the FLTR pin can be used for supplementary signal demodulation. An on-chip, 100 Ω series resistance at the output, combined with an external shunt capacitor, creates a low-pass filter response that reduces the residual ripple in the dc output voltage.
The ADL5504 offers excellent temperature stability across a 30 dB range and near 0 dB measurement error across temperature over the top portion of the dynamic range. In addition to its temperature stability, the ADL5504 offers low process variations that further reduce calibration complexity.
The power detector operates from −40°C to +85°C and is available in a 6-ball, 0.8 mm × 1.2 mm, wafer level chip scale package. It is fabricated on a high fT silicon BiCMOS process.
Applications
- Power measurement of W-CDMA, CDMA2000, QPSK-/QAM-based OFDM (LTE and WiMAX), and other complex modulation waveforms
- RF transmitter or receiver power measurement
