AD8363

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.

Applications: