The ADL5506 is a complete, low cost subsystem for the measurement of RF signals in the 30 MHz to 4.5 GHz frequency range, with a typical dynamic range of 45 dB, intended for use in a wide variety of wireless terminal devices. It provides a wider dynamic range and better accuracy than is possible using discrete diode detectors. In particular, its temperature stability is excellent over −40°C to +85°C.
Its high sensitivity allows measurement of low power levels, thus reducing the amount of power that needs to be coupled to the detector. It is essentially a voltage responding device, with a typical dynamic range of 45 dB.
For convenience, the signal is internally ac-coupled, using a 5 pF capacitor and a broadband 50 Ω match, with an external shunt resistor of 52 Ω. This high-pass coupling, with a corner at approximately 19 MHz, determines the lowest operating frequency. Therefore, the source can be dc grounded.
The ADL5506 output increases from approximately 0.14 V to a little over 1 V as the input signal level increases from 1.25 mV rms (−45 dBm) to 224 mV rms (0 dBm). The output is proportional to the logarithm of the input power level; that is, the reading is presented directly in decibels and is scaled about 18 mV/dB at 900 MHz. A capacitor can be connected between the VLOG pin and the CFLT pin when it is desirable to increase the time interval over which averaging of the input waveform occurs.
The ADL5506 is available in a 6-ball WLCSP and consumes 3.8 mA from a 3.0 V supply. When powered down, the typical disable supply current is <1 µA.
Applications
- RSSI and TSSI for wireless terminal devices
- RF transmitter or receiver power measurement
- Automotive RF bidirectional amplifiers
