50 Hz to 6 GHz,

50 dB TruPwr™ Detector

AD8363

Rev. 0

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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

APPLICATIONS

Power amplifier linearization/control loops

Transmitter power controls

Transmitter signal strength indication (TSSI)

RF instrumentation

FUNCTIONAL BLOCK DIAGRAM

TCM2/PWDN

1

CHPF

2

VPOS

3

COMM

VREF

VTGT

VPOS

COMM

4

11

10

9

5

CLPF

6

VOUT

7

VSET

8

16

15

14

13

TEMP

TCM1

INLO

INHI

NC

AD8363

12

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.