LF to 2.5 GHz

TruPwr™ Detector

AD8361

Rev. C

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However, no responsibility is assumed by Analog Devices for its use, nor for any

infringements of patents or other rights of third parties that may result from its use.

Specifications subject to change without notice. No license is granted by implication

or otherwise under any patent or patent rights of Analog Devices. Trademarks and

registered trademarks are the property of their respective owners.

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Tel: 781.329.4700

www.analog.com

FEATURES

Calibrated rms response

Excellent temperature stability

Up to 30 dB input range at 2.5 GHz

700 mV rms, 10 dBm, re 50 Ω maximum input

±0.25 dB linear response up to 2.5 GHz

Single-supply operation: 2.7 V to 5.5 V

Low power: 3.3 mW at 3 V supply

Rapid power-down to less than 1 µA

APPLICATIONS

Measurement of CDMA, W-CDMA, QAM, other complex

modulation waveforms

RF transmitter or receiver power measurement

GENERAL DESCRIPTION

The AD8361 is a mean-responding power detector for use in

high frequency receiver and transmitter signal chains, up to

2.5 GHz. It is very easy to apply. It requires a single supply only

between 2.7 V and 5.5 V, a power supply decoupling capacitor,

and an input coupling capacitor in most applications. The

output is a linear-responding dc voltage with a conversion gain

of 7.5 V/V rms. An external filter capacitor can be added to

increase the averaging time constant.

RFIN (V rms)

3.0

1.6

0.50.1 0.2 0.3 0.4

2.6

2.2

2.0

1.8

2.8

2.4

V rms (Volts)

1.4

1.2

1.0

0.6

0.8

0.4

0.2

0.0

SUPPLY

REFERENCE MODE

INTERNAL

REFERENCE MODE

GROUND

REFERENCE MODE

01088-C-001

Figure 1. Output in the Three Reference Modes, Supply 3 V, Frequency 1.9 GHz

(6-Lead SOT-23 Package Ground Reference Mode Only)

FUNCTIONAL BLOCK DIAGRAMS

RFIN

IREF

PWDN

VPOS

FLTR

SREF

VRMS

COMM

BAND-GAP

REFERENCE

ERROR

AMP

AD8361

INTERNAL FILTER

ADD

OFFSET

TRANS-

CONDUCTANCE

CELLS

× 7.5

BUFFER

01088-C-002

Figure 2. 8-Lead MSOP

RFIN

IREF

PWDN

VPOS

FLTR

VRMS

COMM

BAND-GAP

REFERENCE

ERROR

AMP

AD8361

INTERNAL FILTER

TRANS-

CONDUCTANCE

CELLS

× 7.5

BUFFER

01088-C-003

Figure 3. 6-Lead SOT-23

The AD8361 is intended for true power measurement of simple

and complex waveforms. The device is particularly useful for

measuring high crest-factor (high peak-to-rms ratio) signals,

such as CDMA and W-CDMA.

The AD8361 has three operating modes to accommodate a

variety of analog-to-digital converter requirements:

1. Ground reference mode, in which the origin is zero.

2. Internal reference mode, which offsets the output 350 mV

above ground.

3. Supply reference mode, which offsets the output to V

/7.5.

The AD8361 is specified for operation from −40°C to +85°C

and is available in 8-lead MSOP and 6-lead SOT-23 packages. It

is fabricated on a proprietary high f

silicon bipolar process.

AD8361

Rev. C | Page 2 of 24

TABLE OF CONTENTS

Specifications..................................................................................... 3

Absolute Maximum Ratings............................................................ 4

ESD Caution.................................................................................. 4

Pin Configuration and Function Descriptions............................. 5

Typical Performance Characteristics ............................................. 6

Circuit Description......................................................................... 11

Applications..................................................................................... 12

Output Reference Temperature Drift Compensation ........... 16

Evaluation Board ............................................................................ 21

Characterization Setups............................................................. 23

Outline Dimensions....................................................................... 24

Ordering Guide .......................................................................... 24

REVISION HISTORY

8/04—Data Sheet Changed from Rev. B to Rev. C.

Changed Trimpots to Trimmable Potentiometers .........Universal

Changes to Specifications................................................................ 3

Changed Using the AD8361 Section Title to Applications ....... 12

Changes to Figure 43...................................................................... 14

Changes to Ordering Guide .......................................................... 24

Updated Outline Dimensions ....................................................... 24

2/01—Data Sheet Changed from Rev. A to Rev. B.

AD8361

Rev. C | Page 3 of 24

SPECIFICATIONS

= 25°C, V

= 3 V, f

= 900 MHz, ground reference output mode, unless otherwise noted.

Table 1.

Parameter Condition Min Typ Max Unit

SIGNAL INPUT INTERFACE (Input RFIN)

Frequency Range

2.5 GHz

Linear Response Upper Limit V

= 3 V 390 mV rms

Equivalent dBm, re 50 Ω 4.9 dBm

= 5 V 660 mV rms

Equivalent dBm, re 50 Ω 9.4 dBm

Input Impedance

225||1 Ω||pF

RMS CONVERSION (Input RFIN to Output V rms)

Conversion Gain 7.5 V/V rms

= 100 MHz, V

= 5 V 6.5 8.5 V/V rms

Dynamic Range Error Referred to Best Fit Line

±0.25 dB Error

CW Input, −40°C < T

< +85°C 14 dB

±1 dB Error CW Input, −40°C < T

< +85°C 23 dB

±2 dB Error CW Input, −40°C < T

< +85°C 26 dB

CW Input, V

= 5 V, −40°C < T

< +85°C 30 dB

Intercept-Induced Dynamic Internal Reference Mode 1 dB

Range Reduction

5, 6

Supply Reference Mode, V

= 3.0 V 1 dB

Supply Reference Mode, V

= 5.0 V 1.5 dB

Deviation from CW Response 5.5 dB Peak-to-Average Ratio (IS95 Reverse Link) 0.2 dB

12 dB Peak-to-Average Ratio (W-CDMA 4 Channels) 1.0 dB

18 dB Peak-to-Average Ratio (W-CDMA 15 Channels) 1.2 dB

OUTPUT INTERCEPT

Inferred from Best Fit Line

Ground Reference Mode (GRM) 0 V at SREF, V

at IREF 0 V

= 100 MHz, V

= 5 V −50 +150 mV

Internal Reference Mode (IRM) 0 V at SREF, IREF Open 350 mV

= 100 MHz, V

= 5 V 300 500 mV

Supply Reference Mode (SRM) 3 V at IREF, 3 V at SREF 400 mV

at IREF, V

at SREF V

/7.5 V

= 100 MHz, V

= 5 V 590 750 mV

POWER-DOWN INTERFACE

PWDN HI Threshold 2.7 ≤ V

≤ 5.5 V, −40°C < T

< +85°C V

− 0.5 V

PWDN LO Threshold 2.7 ≤ V

≤ 5.5 V, −40°C < T

< +85°C 0.1 V

Power-Up Response Time 2 pF at FLTR Pin, 224 mV rms at RFIN 5 µs

100 nF at FLTR Pin, 224 mV rms at RFIN 320 µs

PWDN Bias Current <1 µA

POWER SUPPLIES

Operating Range −40°C < T

< +85°C 2.7 5.5 V

Quiescent Current 0 mV rms at RFIN, PWDN Input LO

1.1 mA

Power-Down Current GRM or IRM, 0 mV rms at RFIN, PWDN Input HI <1 µA

SRM, 0 mV rms at RFIN, PWDN Input HI 10 × V

µA

Operation at arbitrarily low frequencies is possible; see Ap section. plications

Applications

Figure 17 and Figure 47 show impedance versus frequency for the MSOP and SOT-23, respectively.

Calculated using linear regression.

Compensated for output reference temperature drift; see section.

SOT-23-6L operates in ground reference mode only.

The available output swing, and hence the dynamic range, is altered by both supply voltage and reference mode; see Figure 39 and Figure 40.

Supply current is input level dependant; see Figure 16.

Part #	AD8361ARMZ
Description	MINSO DC-2.5GHZ TRUE PWR DETECTOR/CNTRLR
Category	IC
Availability	In Stock
Qty	15

Qty	Price
1 - 3	$5.79943
4 - 6	$4.61319
7 - 9	$4.34957
10 - 12	$4.04203
13 +	$3.60268

AD8361ARMZ

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