ANALOG DEVICES AD8319 Service Manual
1 MHz to 10 GHz, 45 dB
VOUT
V
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FEATURES
Wide bandwidth: 1 MHz to 10 GHz
High accuracy: ±1.0 dB over temperature
45 dB dynamic range up to 8 GHz
Stability over temperature: ±0.5 dB
Low noise measurement/controller output VOUT
Pulse response time (fall/rise): 6 ns/10 ns
Small footprint: 2 mm × 3 mm LFCSP
Supply operation: 3.0 V to 5.5 V @ 22 mA
Fabricated using high speed SiGe process
APPLICATIONS
RF transmitter PA setpoint controls and level monitoring
Power monitoring in radiolink transmitters
RSSI measurement in base stations, WLANs, WiMAX,
and r
adars
GENERAL DESCRIPTION
The AD8319 is a demodulating logarithmic amplifier, capable
of accurately converting an RF input signal to a corresponding
decibel-scaled output. It employs the progressive compression
technique over a cascaded amplifier chain, each stage of which
is equipped with a detector cell. The device can be used in either
measurement or controller modes. The AD8319 maintains
accurate log conformance for signals of 1 MHz to 8 GHz and
provides useful operation to 10 GHz. The input dynamic range
is typically 45 dB (re: 50 Ω) with error less than ±3 dB. The
AD8319 has 6 ns/10 ns (fall time/rise time) response time that
enables RF burst detection to a pulse rate of beyond 50 MHz.
The device provides unprecedented logarithmic intercept stability
vs. ambient temperature conditions. A supply of 3.0 V to 5.5 V
is required to power the device. Current consumption is typically
22 mA, and it decreases to 200 µA when the device is disabled.
The AD8319 can be configured to provide a control voltage to
a p
ower amplifier or a measurement output from the VOUT
pin. Because the output can be used for controller applications,
special attention was paid to minimize wideband noise. In this
mode, the setpoint control voltage is applied to the VSET pin.
Log Detector/Controller
AD8319
FUNCTIONAL BLOCK DIAGRAM
POS
GAIN
BIAS
DET DET DET DET
INHI
INLO
The feedback loop through an RF amplifier is closed via VOUT,
e output of which regulates the output of the amplifier to a
th
magnitude corresponding to V
(V
− 0.1 V) output capability at the VOUT pin, suitable for
POS
controller applications. As a measurement device, VOUT is
externally connected to VSET to produce an output voltage,
V
, that is a decreasing linear-in-dB function of the RF input
OUT
signal amplitude.
The logarithmic slope is −22 mV/dB, determined by the VSET
in
terface. The intercept is 15 dBm (re: 50 Ω, CW input) using
the INHI input. These parameters are very stable against supply
and temperature variations.
The AD8319 is fabricated on a SiGe bipolar IC process and is
a
vailable in a 2 mm × 3 mm, 8-lead LFCSP for an operating
temperature range of −40°C to +85°C.
TADJ
SLOPE
COMM
Figure 1.
. The AD8319 provides 0 V to
SET
IV
IV
VSET
CLPF
05705-001
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2005–2008 Analog Devices, Inc. All rights reserved.
AD8319
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TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Pin Configuration and Function Descriptions............................. 6
Typical Performance Characteristics............................................. 7
Theory of Operation ...................................................................... 10
Using the AD8319 .......................................................................... 11
Basic Connections...................................................................... 11
REVISION HISTORY
4/08—Rev. A to Rev. B
Changes to Features Section and General Description Section. 1
Changes to Theory of Operation Section.................................... 10
Changes to Figure 22 and Setpoint Interface Section................ 11
3/07—Rev. 0 to Rev. A
Changes to Figure 9.......................................................................... 8
Changes to Figure 22 and Setpoint Interface Section................ 11
Changes to Measurement Mode Section..................................... 12
Changes to Layout.......................................................................... 16
Changes to Layout.......................................................................... 17
Updated Outline Dimensions....................................................... 18
10/05—Revision 0: Initial Version
Input Signal Coupling................................................................ 11
Output Interface ......................................................................... 11
Setpoint Interface ....................................................................... 11
Temperature Compensation of Output Voltage..................... 12
Measurement Mode ...................................................................12
Setting the Output Slope in Measurement Mode .................. 13
Controller Mode......................................................................... 13
Output Filtering.......................................................................... 15
Operation Beyond 8 GHz ......................................................... 16
Evaluation Board ............................................................................ 17
Outline Dimensions .......................................................................19
Ordering Guide .......................................................................... 19
Rev. B | Page 2 of 20
AD8319
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SPECIFICATIONS
V
= 3 V, C
POS
Table 1.
Parameter Conditions Min Typ Max Unit
SIGNAL INPUT INTERFACE INHI (Pin 1)
Specified Frequency Range
DC Common-Mode Voltage V
MEASUREMENT MODE
f = 900 MHz R
Input Impedance 1500||0.33 Ω||pF
±1 dB Dynamic Range
−40°C < TA < +85°C 40 dB
Maximum Input Level ±1 dB error −3 dBm
Minimum Input Level ±1 dB error −43 dBm
Slope
Intercept
Output Voltage: High Power In PIN = −10 dBm 0.57 V
Output Voltage: Low Power In PIN = −40 dBm 1.25 V
f = 1.9 GHz R
Input Impedance 950||0.38 Ω||pF
±1 dB Dynamic Range
−40°C < TA < +85°C 40 dB
Maximum Input Level ±1 dB error −4 dBm
Minimum Input Level ±1 dB error −44 dBm
Slope
Intercept
Output Voltage: High Power In PIN = −10 dBm 0.53 V
Output Voltage: Low Power In PIN = −35 dBm 1.19 V
f = 2.2 GHz R
Input Impedance 810||0.39 Ω||pF
±1 dB Dynamic Range
−40°C < TA < +85°C 40 dB
Maximum Input Level ±1 dB error −5 dBm
Minimum Input Level ±1 dB error −45 dBm
Slope
Intercept
Output Voltage: High Power In PIN = −10 dBm 0.5 V
Output Voltage: Low Power In PIN = −35 dBm 1.18 V
f = 3.6 GHz R
Input Impedance 300||0.33 Ω||pF
±1 dB Dynamic Range
−40°C < TA < +85°C 36 dB
Maximum Input Level ±1 dB error −6 dBm
Minimum Input Level ±1 dB error −46 dBm
Slope
Intercept
Output Voltage: High Power In PIN = −10 dBm 0.46 V
Output Voltage: Low Power In PIN = −40 dBm 1.14 V
= 1000 pF, TA = 25°C, 52.3 Ω termination resistor at INHI, unless otherwise noted.
LPF
0.001 10 GHz
VOUT (Pin 5) shorted to VSET (Pin 4),
sinusoid
T
1
1
−25 −22 −19.5 mV/dB
12 15 21 dBm
T
1
1
−25 −22 −19.5 mV/dB
10 13 20 dBm
T
1
1
−22 mV/dB
13 dBm
T
1
1
−22 mV/dB
10 dBm
al input signal
= 18 kΩ
TAD J
= 25°C 40 dB
A
= 8 kΩ
TAD J
= 25°C 40 dB
A
= 8 kΩ
TAD J
= 25°C 40 dB
A
= 8 kΩ
TAD J
= 25°C 40 dB
A
− 0.6 V
POS
Rev. B | Page 3 of 20
AD8319
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Parameter Conditions Min Typ Max Unit
f = 5.8 GHz R
Input Impedance 110||0.05 Ω||pF
±1 dB Dynamic Range
−40°C < TA < +85°C 40 dB
Maximum Input Level ±1 dB error −3 dBm
Minimum Input Level ±1 dB error −43 dBm
1
Slope
Intercept
1
Output Voltage: High Power In PIN = −10 dBm 0.57 V
Output Voltage: Low Power In PIN = −40 dBm 1.25 V
f = 8.0 GHz R
Input Impedance 28||0.79 Ω||pF
±1 dB Dynamic Range
−40°C < TA < +85°C 31 dB
Maximum Input Level ±1 dB error −1 dBm
Minimum Input Level ±1 dB error −41 dBm
2
Slope
Intercept
2
Output Voltage: High Power In PIN = −10 dBm 0.67 V
Output Voltage: Low Power In PIN = −40 dBm 1.34 V
OUTPUT INTERFACE VOUT (Pin 5)
Voltage Swing V
V
Output Current Drive V
Small Signal Bandwidth RFIN = −10 dBm; from CLPF to VOUT 140 MHz
Output Noise
Fall Time
Rise Time
Video Bandwidth (or Envelope Bandwidth) 50 MHz
VSET INTERFACE VSET (Pin 4)
Nominal Input Range RFIN = 0 dBm; measurement mode 0.35 V
RFIN = −40 dBm; measurement mode 1.23 V
Logarithmic Scale Factor −45 dB/V
Input Resistance RFIN = −20 dBm; controller mode; V
TAD J INTERFACE TADJ ( Pin 6)
Input Resistance TADJ = 0.9 V, sourcing 50 μA 40 kΩ
Disable Threshold Voltage TADJ = open V
POWER INTERFACE VPOS (Pin 7)
Supply Voltage 3.0 5.5 V
Quiescent Current 18 22 30 mA
vs. Temperature
Disable Current TADJ = VPOS 200 μA
1
Slope and intercept are determined by calculating the best fit line between the power levels of −40 dBm and −10 dBm at the specified input frequency.
2
Slope and intercept are determined by calculating the best fit line between the power levels of −34 dBm and −16 dBm at 8.0 GHz.
= 500 Ω
TAD J
T
= 25°C 40 dB
A
−22 mV/dB
15 dBm
= open
TAD J
T
= 25°C 40 dB
A
−22 mV/dB
20 dBm
= 0 V; RFIN = open V
SET
= 1.5 V; RFIN = open 10 mV
SET
= 0 V; RFIN = open 10 mA
SET
RFIN = 2.2 GHz, −10 dBm, f
= open
C
LPF
= 100 kHz,
NOISE
Input level = no signal to −10 dBm, 90% to 10%;
= 8 pF
C
LPF
Input level = no signal to −10 dBm, 90% to 10%;
C
= open; R
LPF
= 150 Ω
OUT
Input level = −10 dBm to no signal, 10% to 90%;
= 8 pF
C
LPF
Input level = −10 dBm to no signal, 10% to 90%;
= open; R
C
LPF
−40°C ≤ T
= 150 Ω
OUT
≤ +85°C
A
Rev. B | Page 4 of 20
= 1 V 40 kΩ
SET
90 nV/√Hz
18 ns
6 ns
20 ns
10 ns
60 μA/°C
− 0.1 V
POS
− 0.4 V
POS
AD8319
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ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage: V
V
Voltage 0 to V
SET
Input Power (Single-Ended, re: 50 Ω) 12 dBm
Internal Power Dissipation 0.73 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 (Soldering, 60 sec) 260°C
POS
5.7 V
POS
55°C/W
Stresses above those listed under Absolute Maximum Ratings
y cause permanent damage to the device. This is a stress
ma
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.
ESD CAUTION
Rev. B | Page 5 of 20
AD8319
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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
1INHI
AD8319
2COMM
TOP VIEW
3CLPF
(Not to Scale)
4VSET
Figure 2. Pin Configuration
8INLO
7 VPOS
6 TADJ
5VOUT
05705-002
Table 3. Pin Function Descriptions
Pin No. Mnemonic Description
1 INHI RF Input. Nominal input range of −50 dBm to 0 dBm, re: 50 Ω; ac-coupled RF input.
2 COMM Device Common. Connect this pin to a low impedance ground plane.
3 CLPF
4 VSET Setpoint Control Input for Controller Mode or Feedback Input for Measurement Mode.
5 VOUT
6 TADJ
7 VPOS Positive Supply Voltage, 3.0 V to 5.5 V.
8 INLO RF Common for INHI. AC-coupled RF common.
Paddle The paddle is internally connected to COMM; solder to a low impedance ground plane.
Loop Filter Capacitor. In measurement mode, this capacitor sets
In controller mode, the capacitance on this node sets the response time of the error amplifier/integrator.
Measurement and Controller Output. I
representation of the RF input signal amplitude. In controller mode, VOUT is used to control the gain of a VGA or
VVA with a positive gain sense (increasing voltage increases gain).
Temperature Compensation Adjustment. Frequency dependen
a ground referenced resistor to this pin.
n measurement mode, VOUT provides a decreasing linear-in-dB
the pulse response time and video bandwidth.
t temperature compensation is set by connecting
Rev. B | Page 6 of 20
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