REV. A

Information furnished by Analog Devices is believed to be accurate and

reliable. However, no responsibility is assumed by Analog Devices for its

use, nor for any infringements of patents or other rights of third parties

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

AD8361

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700 World Wide Web Site: http://www.analog.com

Fax: 781/326-8703 © Analog Devices, Inc., 2000

LF to 2.5 GHz

TruPwr

™

Detector

FUNCTIONAL BLOCK DIAGRAMS

micro_SOIC

RFIN

IREF

PWDN

VPOS

FLTR

SREF

VRMS

COMM

BAND-GAP

REFERENCE

ERROR

AMP

␹

AD8361

INTERNAL FILTER

ADD

OFFSET

TRANS-

CONDUCTANCE

CELLS

ⴛ 7.5

BUFFER

SOT-23-6L

RFIN

PWDN

VPOS

FLTR

VRMS

COMM

BAND-GAP

REFERENCE

␹

AD8361

INTERNAL FILTER

TRANS-

CONDUCTANCE

CELLS

ERROR

AMP

ⴛ 7.5

BUFFER

FEATURES

Calibrated RMS Response

Excellent Temperature Stability

Up to 30 dB Input Range at 2.5 GHz

700 mV rms, 10 dBm re 50 ⍀ Maximum Input

ⴞ0.25 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 ␮A

APPLICATIONS

Measurement of CDMA, W-CDMA, QAM, Other

Complex Modulation Waveforms

RF Transmitter or Receiver Power Measurement

PRODUCT 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 only a single supply between

2.7 V and 5.5 V, 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 averag-

ing 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

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

Frequency 1.9 GHz (SOT-23-6L Package Ground Reference

Mode Only)

TruPwr is a trademark of Analog Devices, Inc.

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 referenced 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 micro_SOIC and 6-lead SOT packages.

It is fabricated on a proprietary high f

silicon bipolar process.

–2–

REV. A

AD8361–SPECIFICATIONS

= 25ⴗC, V

= 3 V, f

= 900 MHz, ground reference output mode, unless otherwise

noted.)

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储1 Ω储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°C14dB

±1 dB Error CW Input, –40°C < T

< +85°C23dB

±2 dB Error CW Input, –40°C < T

< +85°C26dB

CW Input, V

= 5 V, –40°C < T

< +85°C30dB

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) 0 V at IREF, 3 V at SREF 400 mV

= 100 MHz, V

= 5 V 590 750 mV

0 V at IREF, V

at SREF V

/7.5 V

POWER-DOWN INTERFACE

PWDN HI Threshold 2.7

≤

5.5 V, –40°C < T

< +85°CV

– 0.5 V

PWDN LO Threshold 2.7

≤

5.5 V, –40°C < T

< +85°C0.1V

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°C2.75.5V

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

NOTES

Operation at arbitrarily low frequencies is possible; see Applications section.

Figure 13 and Figure 40 show impedance vs. frequency for the micro_SOIC and SOT respectively.

Calculated using linear regression.

Compensated for output reference temperature drift; see Applications 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 Figures 35 and 36.

Supply current is input level dependant; see Figure 12.

Speciﬁcations subject to change without notice.

AD8361

–3–

REV. A

ABSOLUTE MAXIMUM RATINGS

Supply Voltage V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V

SREF, PWDN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V, V

IREF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

– 0.3 V, V

RFIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 V rms

Equivalent Power re 50 Ω . . . . . . . . . . . . . . . . . . . 13 dBm

Internal Power Dissipation

. . . . . . . . . . . . . . . . . . . . 200 mW

SOT-23-6L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 mW

micro_SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 mW

Maximum Junction Temperature . . . . . . . . . . . . . . . . . 125°C

Operating Temperature Range . . . . . . . . . . . –40°C to +85°C

Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C

Lead Temperature Range (Soldering 60 sec) . . . . . . . . . 300°C

NOTES

Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the

device at these or any other conditions above those indicated in the operational

section of this speciﬁcation is not implied. Exposure to absolute maximum rating

conditions for extended periods may affect device reliability.

Specification is for the device in free air.

SOT-23-6L: θ

= 230°C/W; θ

= 92°C/W.

micro_SOIC: θ

= 200°C/W; θ

= 44°C/W.

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily

accumulate on the human body and test equipment and can discharge without detection. Although

the AD8361 features proprietary ESD protection circuitry, permanent damage may occur on

devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are

recommended to avoid performance degradation or loss of functionality.

PIN FUNCTION DESCRIPTIONS

Micro SOT Name Description

1 6 VPOS Supply Voltage Pin. Operational range

2.7 V to 5.5 V.

2 IREF Output Reference Control Pin. Inter-

nal reference mode enabled when pin

is left open. Otherwise, this pin should

be tied to VPOS. DO NOT ground this

pin.

3 5 RFIN Signal Input Pin. Must be driven from

an ac-coupled source. The low frequency

real input impedance is 225 Ω.

4 4 PWDN Power-Down Pin. For the device to

operate as a detector it needs a logical

low input (less than 100 mV). When

a logic high (greater than V

– 0.5 V)

is applied, the device is turned off and

the supply current goes to nearly zero

(ground and internal reference mode

less than 1 µA, supply reference mode

divided by 100 kΩ).

5 2 COMM Device Ground Pin.

6 3 FLTR By placing a capacitor between this pin

and VPOS, the corner frequency of the

modulation ﬁlter is lowered. The on-

chip ﬁlter is formed with 27 pF储2 kΩ

for small input signals.

7 1 VRMS Output Pin. Near-rail-to-rail voltage

output with limited current drive capa-

bilities. Expected load >10 kΩ to ground.

8 SREF Supply Reference Control Pin. To en-

able supply reference mode this pin

must be connected to VPOS, other-

wise it should be connected to COMM

(ground).

PIN CONFIGURATIONS

micro_SOIC

AD8361

VPOS

IREF

RFIN

PWDN

SREF

VRMS

FLTR

COMM

SOT-23-6L

VPOS

RFIN

PWDN

VRMS

FLTR

COMM

AD8361

ORDERING GUIDE

Model Temperature Range Package Description Package Option

AD8361ARM* –40°C to +85°C Tube, 8-Lead micro_SOIC RM-8

AD8361ARM-REEL 13" Tape and Reel

AD8361ARM-REEL7 7" Tape and Reel

AD8361ART-REEL 13" Tape and Reel RT-6

AD8361ART-REEL7 7" Tape and Reel

AD8361-EVAL Evaluation Board micro_SOIC

AD8361ART-EVAL Evaluation Board SOT-23-6L

*Device branded as J3A.

WARNING!

ESD SENSITIVE DEVICE

Part #	AD8361-ARM
Description
Category	IC
Availability	In Stock
Qty	14

Qty	Price
1 - 2	$16.07215
3 - 5	$12.78466
6 - 8	$12.05411
9 - 11	$11.20180
12 +	$9.98421

AD8361-ARM

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