IC, LOGARITHMIC AMP, 12NS, LFCSP-16

AD8318ACPZ-REEL7

Manufacturer Part NumberAD8318ACPZ-REEL7
DescriptionIC, LOGARITHMIC AMP, 12NS, LFCSP-16
ManufacturerAnalog Devices Inc
AD8318ACPZ-REEL7 datasheet
 


Specifications of AD8318ACPZ-REEL7

No. Of Amplifiers1Dynamic Range, Decades70
Response Time12nsSupply Voltage Range4.5V To 5.5V
Amplifier Case StyleLFCSPNo. Of Pins16
Supply Current68mADesign ResourcesStable, Closed-Loop Automatic Power Control for RF Appls (CN0050) Software Calibrated, 1 MHz to 8 GHz, 70 dB RF Power Measurement System Using AD8318 (CN0150)
Frequency1MHz ~ 8GHzRf TypeRADAR, 802.11/Wi-Fi, 8.2.16/WiMax, Wireless LAN
Input Range-60dBm ~ -2dBmAccuracy±1dB
Voltage - Supply4.5 V ~ 5.5 VCurrent - Supply68mA
Package / Case16-VQFN, CSP Exposed PadRohs CompliantYes
Lead Free Status / RoHS StatusLead free / RoHS CompliantOther namesAD8318ACPZ-REEL7
AD8318ACPZ-REEL7TR
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FEATURES
Wide bandwidth: 1 MHz to 8 GHz
High accuracy: ±1.0 dB over 55 dB range (f < 5.8 GHz)
Stability over temperature: ±0.5 dB
Low noise measurement/controller output (VOUT)
Pulse response time: 10 ns/12 ns (fall/rise)
Integrated temperature sensor
Small footprint LFCSP
Power-down feature: <1.5 mW at 5 V
Single-supply operation: 5 V @ 68 mA
Fabricated using high speed SiGe process
APPLICATIONS
RF transmitter PA setpoint control and level monitoring
RSSI measurement in base stations, WLAN, WiMAX, and
radars
GENERAL DESCRIPTION
The AD8318 is a demodulating logarithmic amplifier, capable
of accurately converting an RF input signal to a corresponding
decibel-scaled output voltage. It employs the progressive
compression technique over a cascaded amplifier chain, each
stage of which is equipped with a detector cell. The device is
used in measurement or controller mode. The AD8318
maintains accurate log conformance for signals of 1 MHz to
6 GHz and provides useful operation to 8 GHz. The input range
is typically 60 dB (re: 50 Ω) with error less than ±1 dB. The
AD8318 has a 10 ns response time that enables RF burst
detection to beyond 45 MHz. The device provides unprece-
dented logarithmic intercept stability vs. ambient temperature
conditions. A 2 mV/°C slope temperature sensor output is also
provided for additional system monitoring. A single supply of
5 V is required. Current consumption is typically 68 mA. Power
consumption decreases to <1.5 mW when the device is disabled.
The AD8318 can be configured to provide a control voltage
to a VGA, such as a power amplifier or a measurement output,
from Pin VOUT. Because the output can be used for controller
applications, wideband noise is minimal.
Rev. B
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. 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.
1 MHz to 8 GHz, 70 dB
Logarithmic Detector/Controller
FUNCTIONAL BLOCK DIAGRAM
VPSI
ENBL
TEMP
GAIN
TEMP
SLOPE
SENSOR
BIAS
DET
DET
DET
INHI
INLO
CMIP
Figure 1.
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
–65
–60 –55 –50 –45 –40 –35 –30 –25 –20 –15 –10 –5
P
(dBm)
IN
Figure 2. Typical Logarithmic Response and Error vs. Input Amplitude at 5.8 GHz
In this mode, the setpoint control voltage is applied to VSET.
The feedback loop through an RF amplifier is closed via VOUT,
the output of which regulates the amplifier output to a magnitude
corresponding to VSET. The AD8318 provides 0 V to 4.9 V
output capability at the VOUT pin, suitable for controller
applications. As a measurement device, Pin VOUT is externally
connected to VSET to produce an output voltage, V
is a decreasing linear-in-dB function of the RF input signal
amplitude.
The logarithmic slope is nominally −25 mV/dB but can be
adjusted by scaling the feedback voltage from VOUT to the
VSET interface. The intercept is 20 dBm (re: 50 Ω, CW input)
using the INHI input. These parameters are very stable against
supply and temperature variations.
The AD8318 is fabricated on a SiGe bipolar IC process and is
available in a 4 mm × 4 mm, 16-lead LFCSP for the operating
o
temperature range of –40
C to +85
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
©2004-2007 Analog Devices, Inc. All rights reserved.
AD8318
TADJ
VPSO
I
V
VSET
VOUT
I
V
DET
CLPF
CMOP
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
0
5
10
which
OUT,
o
C.
www.analog.com

AD8318ACPZ-REEL7 Summary of contents

  • Page 1

    FEATURES Wide bandwidth: 1 MHz to 8 GHz High accuracy: ±1.0 dB over 55 dB range (f < 5.8 GHz) Stability over temperature: ±0.5 dB Low noise measurement/controller output (VOUT) Pulse response time: 10 ns/12 ns (fall/rise) Integrated temperature sensor ...

  • Page 2

    AD8318 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 6 ESD Caution.................................................................................. 6 Pin Configuration and Function Descriptions............................. 7 Typical Performance Characteristics ...

  • Page 3

    SPECIFICATIONS 220 pF 25°C, 52.3 Ω termination resistor at INHI, unless otherwise noted. POS LPF A Table 1. Parameter SIGNAL INPUT INTERFACE Specified Frequency Range DC Common-Mode Voltage MEASUREMENT MODE f = ...

  • Page 4

    AD8318 Parameter f = 3.6 GHz Input Impedance ±3 dB Dynamic Range ±1 dB Dynamic Range Maximum Input Level Minimum Input Level Slope Intercept Output Voltage—High Power In Output Voltage—Low Power In Temperature Sensitivity f = 5.8 GHz Input Impedance ...

  • Page 5

    Parameter VSET INTERFACE Nominal Input Range Logarithmic Scale Factor Bias Current Source TEMPERATURE REFERENCE Output Voltage Temperature Slope Current Source/Sink POWER-DOWN INTERFACE Logic Level to Enable Device ENBL Current When Enabled ENBL Current When Disabled POWER INTERFACE Supply Voltage Quiescent ...

  • Page 6

    AD8318 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Supply Voltage: Pin VPSO, Pin VPSI ENBL, V Voltage SET Input Power (Single-Ended, re: 50 Ω) Internal Power Dissipation 1 θ JA Maximum Junction Temperature Operating Temperature Range Storage Temperature Range Lead Temperature ...

  • Page 7

    PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 3. Pin Function Descriptions Pin No. Mnemonic Description 1, 2, 11, 12 CMIP Device Common (Input System Ground VPSI Positive Supply Voltage (Input System): 4 5.5 V. Voltage on Pin ...

  • Page 8

    AD8318 TYPICAL PERFORMANCE CHARACTERISTICS +25°C, −40°C, +85°C; C POS A +85°C Red. 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 –65 –55 –45 –35 –25 –15 P (dBm) IN Figure 4. ...

  • Page 9

    P (dBm) IN Figure 10. Distribution of Error over Temperature After Ambient Normalization vs. Input Amplitude at 900 MHz for at Least 70 ...

  • Page 10

    AD8318 j1 j0.5 j0.2 0 0.2 0.5 1 8GHz 5.8GHz –j0.2 3.6GHz –j0.5 START FREQUENCY = 0.1GHz –j1 STOP FREQUENCY = 8GHz Figure 16. Input Impedance vs. Frequency; No Termination Resistor on INHI Ω O 0.07 0.06 ...

  • Page 11

    THEORY OF OPERATION The AD8318 is a 9-stage demodulating logarithmic amplifier that provides RF measurement and power amplifier control functions. The design of the AD8318 is similar to the logarithmic detector/controller. However, the AD8318 input frequency range extends to 8 ...

  • Page 12

    AD8318 USING THE AD8318 BASIC CONNECTIONS The AD8318 is specified for operation GHz result, low impedance supply pins with adequate isolation between functions are essential. In the AD8318, VPSI and VPSO, the two positive supply ...

  • Page 13

    VPSI CURRENT 10pF 10pF 20kΩ 20kΩ INHI 2kΩ INLO gm STAGE Figure 26. Input Interface While the input can be reactively matched, this is typically not necessary. An external 52.3 Ω shunt resistor (connected on the signal side of the ...

  • Page 14

    AD8318 Table 5 lists recommended resistors for various frequencies. These resistors provide the best overall temperature drift based on measurements of a diverse population of devices. The relationship between output temperature drift and frequency is nonlinear and is not easily ...

  • Page 15

    The maximum output voltage is 2.1 V × X, and cannot exceed 400 mV below the positive supply (2.1 V × X) when X < (V − 400 mV)/(2.1 V) OUT(MAX) POS − 400 mV) ...

  • Page 16

    AD8318 Using the equation for the ideal output voltage (see Equation 13 reference, the log conformance error of the measured data can be calculated as Error (dB − V OUT(MEASURED) OUT(IDEAL) Figure 32 includes a plot ...

  • Page 17

    V +25°C ERROR +25°C wrt V OUT 2.0 V –40°C ERROR –40°C wrt V OUT V +85°C ERROR +85°C wrt V OUT 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 –65 –60 –55 –50 –45 –40 –35 –30 ...

  • Page 18

    AD8318 PULSED RF INPUT 1nF 1nF Figure 39. AD8318 Operating with the High Speed ADCMP563 Comparator RESPONSE TIME CAPABILITY The AD8318 has rise/fall time capability (10% to 90%) for input power switching between the noise floor and ...

  • Page 19

    In many log amp applications, it may be necessary to lower the corner frequency of the postdemodulation filtering to achieve low output ripple while maintaining a rapid response time to changes in signal level. For an example of a 4-pole ...

  • Page 20

    AD8318 0 –5 –10 –15 –20 –25 –30 –35 –40 –45 –50 –55 –60 0.6 0.8 1.0 1.2 1.4 V (V) SET Figure 44. AD8367 Output Power vs. AD8318 Setpoint Voltage For the AGC loop to remain locked, the AD8318 ...

  • Page 21

    CHARACTERIZATION SETUP AND METHODS The general hardware configuration used for the AD8318 characterization is shown in Figure 47. The primary setup used for characterization is measurement mode. The characterization board is similar to the customer evaluation board with the exception ...

  • Page 22

    AD8318 EVALUATION BOARD Table 6. Evaluation Board (Rev. A) Bill of Materials Component Function VP, GND Supply and Ground Connections SW1, R3 Device Enable. When in Position A, the ENBL pin is connected to VP and the AD8318 is in ...

  • Page 23

    R2 1kΩ T EMP C1 1nF R1 R 52.3Ω C2 1nF FIN POS NBL R3 SW1 10kΩ Figure 48. Evaluation Board Schematic Figure 49. Component Side Layout V POS R4 C5 499Ω R5 0.1µF 0Ω C6 ...

  • Page 24

    ... AD8318 OUTLINE DIMENSIONS PIN 1 INDICATOR 12° MAX 1.00 0.85 0.80 ORDERING GUIDE Model Temperature Range 1 AD8318ACPZ-REEL7 −40°C to +85°C 1 AD8318ACPZ-R2 −40°C to +85° AD8318ACPZ-WP −40°C to +85°C 1 AD8318-EVALZ RoHS compliant part waffle pack. ©2004-2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners ...