Analog Devices AD8367ARU-REEL-7, AD8367ARU-REEL, AD8367ARU, AD8367 Datasheet

500 MHz, Linear-in-dB VGA

a

FEATURES
Broad Range Analog Variable Gain

–2.5 dB to +42.5 dB
3 dB Cutoff Frequency of 500 MHz
Gain Up and Gain Down Modes
Linear-in-dB, Scaled 20 mV/dB
Resistive Ground Referenced Input

Nominal Z
On-Chip Square-Law Detector
Single-Supply Operation: 2.7 V to 5.5 V

APPLICATIONS
Cellular Base Station
Broadband Access
Power Amplifier Control Loops
Complete, Linear IF AGC Amplifiers
High-Speed Data I/O

GENERAL DESCRIPTION

The AD8367 is a high-performance 45 dB variable gain ampli­fier with linear-in-dB gain control for use from low frequencies
up to several hundred megahertz. The range, flatness, and accu­racy of the gain response are achieved using Analog Devices’

®

X-AMP

architecture, the most recent in a series of powerful
proprietary concepts for variable gain applications, which far
surpasses what can be achieved using competing techniques.

The input is applied to a 200 Ω resistive ladder network, having
nine sections each of 5 dB loss, for a total attenuation of 45 dB.
At maximum gain, the first tap is selected; at progressively lower
gains, the tap moves smoothly and continuously toward higher
attenuation values. The attenuator is followed by a 42.5 dB
fixed gain feedback amplifier—essentially an operational ampli­fier with a gain bandwidth product of 100 GHz—and is very
linear, even at high frequencies. The output third order intercept is
+20 dBV at 100 MHz (+27 dBm re 200 Ω), measured at an
output level of 1 V p-p with V

ⴝ 200 ⍀

IN

= 5 V.

S

with AGC Detector

AD8367

FUNCTIONAL BLOCK DIAGRAM

VPSOVPSI

ICOM

INPT

ICOM

CELLS

AD8367

9-STAGE ATTENUATOR BY 5dB

g

m

GAUSSIAN INTERPOLATOR

The analog gain-control interface is very simple to use. It is
scaled at 20 mV/dB, and the control voltage, V
50 mV at –2.5 dB to 950 mV at +42.5 dB. In the inverse-gain
mode of operation, selected by a simple pin-strap, the gain
decreases from +42.5 dB at V
V

= 950 mV. This inverse mode is needed in AGC applications,

GAIN

= 50 mV to –2.5 dB at

GAIN

which are supported by the integrated square-law detector,
whose set point is chosen to level the output to 354 mV rms,
regardless of the waveshape. A single external capacitor sets up
the loop averaging time.

The AD8367 may be powered on or off by a voltage applied to
the ENBL pin. When this voltage is at a logic LO, the total power
dissipation drops to the milliwatt range. For a logic HI, the chip
powers-up rapidly to its normal quiescent current of 26 mA at
25°C. The AD8367 is available in a 14-lead TSSOP package for
the industrial temperature range of –40°C to +85°C.

ENBL

BIAS

SQUARE

LAW

DETECTOR

DETOGAINMODE

, runs from

GAIN

ICOM

DECL

HPFL

VOUT

OCOM

X-AMP is a registered trademark of Analog Devices, Inc.

REV. 0

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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]www.analog.com
Fax: [phone] © Analog Devices, Inc., 2001

AD8367–SPECIFICATIONS

(VS = 5 V, TA = 25ⴗC, System Impedance ZO = 200 ⍀, V
unless otherwise noted.)

= 5 V, f = 10 MHz,

MODE

Parameter Conditions Min Typ Max Unit

OVERALL FUNCTION

Frequency Range LF 500 MHz
GAIN Range 45 dB

INPUT STAGE Pins INPT and ICOM

Maximum Input To Avoid Input Overload 700 mV p-p
Input Resistance From INPT to ICOM 175 200 225 Ω

GAIN CONTROL INTERFACE Pin GAIN

Scaling Factor V

Gain Law Conformance 100 mV ≤ V
Maximum Gain V
Minimum Gain V
V

Step Response From 0 dB to 30 dB 300 ns

GAIN

= 5 V, 50 mV ≤ V

MODE

= 0 V, 50 mV ≤ V

V

MODE

= 0.95 V +42.5 dB

GAIN

= 0.05 V –2.5 dB

GAIN

≤ 900 mV ± 0.2 dB

GAIN

≤ 950 mV +20 mV/dB

GAIN

≤ 950 mV –20 mV/dB

GAIN

From 30 dB to 0 dB 300 ns

Small Signal Bandwidth V

= 0.5 V 5 MHz

GAIN

OUTPUT STAGE Pin VOUT

Max Output Voltage Swing RL = 1 kΩ 4.3 V p-p

R

= 200 Ω 3.5 V p-p
Output Source Resistance Series Resistance of Output Buffer 50 Ω
Output Centering Voltage

1

L

VS/2 V

SQUARE LAW DETECTOR Pin DETO

Output Set Point 354 mV rms
AGC Small Signal Response Time C

 100 pF, 6 dB Gain Step 1 s

AGC

POWER INTERFACE Pins VPSI, VPSO, ICOM, and OCOM

Supply Voltage 2.7 5.5 V
Total Supply Current ENBL High, Maximum Gain, R

 200 Ω 26 30 mA

L

(Includes Load Current)

Disable Current vs. Temperature ENBL Low 1.3 1.6 mA

–40°C ≤ TA ≤ +85°C 1.8 mA

MODE CONTROL INTERFACE Pin MODE

Mode LO Threshold Device in Negative Slope Mode of Operation 1.2 V
Mode HI Threshold Device in Positive Slope Mode of Operation 1.4 V

ENABLE INTERFACE Pin ENBL

Enable Threshold 2.5 V
Enable Response Time Time Delay Following LO to HI Transition 1.5 s

until Device Meets Full Specifications.

Enable Input Bias Current ENBL at 5 V 27 A

ENBL at 0 V 32 nA

–2–

REV. 0

AD8367

Parameter Conditions Min Typ Max Unit

f = 70 MHz

Gain Maximum Gain +42.5 dB

Minimum Gain –3.7 dB
Gain Scaling Factor 19.9 mV/dB
Gain Intercept –5.6 dB
Noise Figure Maximum Gain 6.2 dB
Output IP3 f1  70 MHz, f2  71 MHz, V

Output 1 dB Compression Point V

 0.5 V 8.5 dBm

GAIN

f = 140 MHz

Gain Maximum Gain +43.5 dB

Minimum Gain –3.6 dB
Gain Scaling Factor 19.7 mV/dB
Gain Intercept –5.3 dB
Noise Figure Maximum Gain 7.4 dB
Output IP3 f1  140 MHz, f2  141 MHz, V

Output 1 dB Compression Point V

 0.5 V 8.4 dBm

GAIN

f = 190 MHz

Gain Maximum Gain +43.5 dB

Minimum Gain –3.8 dB
Gain Scaling Factor 19.6 mV/dB
Gain Intercept –5.3 dB
Noise Figure Maximum Gain 7.5 dB
Output IP3 f1  190 MHz, f2  191 MHz, V

Output 1 dB Compression Point V

 0.5 V 8.4 dBm

GAIN

f = 240 MHz

Gain Maximum Gain +43 dB

Minimum Gain –4.1 dB
Gain Scaling Factor 19.7 mV/dB
Gain Intercept –5.2 dB
Noise Figure Maximum Gain 7.6 dB
Output IP3 f1  240 MHz, f2  241 MHz, V

Output 1 dB Compression Point V

NOTES

1

The output dc centering voltage is normally set at VS2 and can be adjusted by applying a voltage to DECL.

Specifications subject to change without notice.

 0.5 V 8.1 dBm

GAIN

 0.5 V 27.5 dBm

GAIN

20.5 dBV rms

1.5 dBV rms

 0.5 V 24.5 dBm

GAIN

17.5 dBV rms

1.4 dBV rms

 0.5 V 23.9 dBm

GAIN

16.9 dBV rms

1.4 dBV rms

 0.5 V 24.6 dBm

GAIN

17.6 dBV rms

1.1 dBV rms

REV. 0

–3–

AD8367

WARNING!

ESD SENSITIVE DEVICE

ABSOLUTE MAXIMUM RATINGS*

Supply Voltage VPSO, VPSI . . . . . . . . . . . . . . . . . . . . . 5.5 V

ENBL Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . V

MODE Select Voltage . . . . . . . . . . . . . . . . . . . . V

V

Control Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 V

GAIN

+ 200 mV

S

+ 200 mV

S

Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 600 mV

Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . 250 mW

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C/W

θ

JA

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

*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.

PIN CONFIGURATION

ICOM

ENBL

INPT

MODE

GAIN

DETO

ICOM

1

2

3

AD8367

4

TOP VIEW

(Not to Scale)

5

6

7

14

13

12

11

10

9

8

ICOM

HPFL

VPSI

VPSO

VOUT

DECL

OCOM

PIN FUNCTION DESCRIPTIONS

Pin Mnemonic Description

1, 7, 14 ICOM Signal Common. Connect to low

impedance ground.

2 ENBL A HI activates the device.

3 INPT Signal Input. 200 Ω to ground.

4 MODE Gain Direction Control. HI for Positive

Slope; LO for Negative Slope.

5 GAIN Gain-Control Voltage Input

6 DETO Detector Output. Provides output cur-

rent for RSSI function and AGC control.

8 OCOM Power Common. Connect to low

impedance ground.

9 DECL Decoupling Pin. Can Be Used to

Modify the Output Reference Level.

10 VOUT Signal Output. Generally will be

ac-coupled.

11 VPSO Positive Supply Voltage. 2.7 V to 5.5 V.

VPSI and VPSO are tied together inter­nally with back-to-back PN junctions.
They should be tied together externally
and properly bypassed.

12 VPSI Positive Supply Voltage. 2.7 V to 5.5 V.

13 HPFL High-Pass Filter Connection. A capaci-

tor to ground sets the corner frequency
of the output offset control loop.

ORDERING GUIDE

Model Temperature Range Package Description Package Option

AD8367ARU –40°C to +85°C Tube, 14-Lead RU-14
AD8367ARU-REEL-7 –40°C to +85°C 7" Tape and Reel
AD8367-EVAL –40°C to +85°C Evaluation Board
AD8367ARU-REEL –40°C to +85°C 13" Tape and Reel

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 AD8367 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.

–4–

REV. 0

50

FREQUENCY – MHz

10

4

70 25090

NOISE FIGURE – dB

110 130 150 170

190

210 230

9

8

7

6

5

+85 C

+25 C

–40

C

40

30

20

GAIN – dB

10

0

–10

10 1000100

Typical Performance Characteristics–AD8367

1V

0.9V

0.8V

0.7V

0.6V

0.5V

0.4V

0.3V

0.2V

0.1V

FREQUENCY – MHz

TPC 1. Gain vs. Frequency for Values of V

45

40

35

30

5

0

0 1.00.1

5

0

0 1.00.1

MODE ⴝ 5V

10MHz

70MHz
140MHz
240MHz

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

V

– V

GAIN

(Mode LO and Mode HI)

GAIN

V

– V

GAIN

25

20

GAIN – dB

15

10

–5

TPC 2. Gain vs. V

45

40

35

30

25

20

GAIN – dB

15

10

–5

TPC 3. Gain Conformance at 70 MHz for T  –40ⴗC,

ⴗ

C, and +85ⴗC.

+25

MODE ⴝ 0V
10MHz
70MHz
140MHz
240MHz

–40 C

+25 C

+85

GAIN

2.0

1.6

1.2

0.8

0.4

C

0

–0.4

–0.8

–1.2

–1.6

–2.0

LINEARITY ERROR – dB

TPC 4. NF (re 200 Ω) vs. Frequency at Maximum Gain

60

50

40

30

20

NOISE FIGURE – dB

10

0

0 1.00.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

TPC 5. NF (re 200 ) vs. V

30

25

20

15

OIP3 – dBV rms

10

V

GAIN

– V

at 70 MHz

GAIN

10MHz

70MHz

140MHz

240MHz

37

32

27

22

17

5

0

0

0.1 0.2 0.4 0.6 0.7 0.8 0.9 1.0

0.3 0.5
V

– V

GAIN

TPC 6. OIP3 vs. V

GAIN

12

7

OIP3 – dBm (re 200⍀)

REV. 0

–5–