50 dB GSM PA Controller Data Sheet AD8315 Its high sensitivity allows control at low signal levels, thus FEATURES reducing the amount of power that must be coupled to Complete RF detector/controller function the detector. >50 dB range at 0.9 GHz (49 dBm to +2 dBm, re 50 ) Accurate scaling from 0.1 GHz to 2.5 GHz For convenience, the signal is internally ac-coupled. This Temperature-stable linear-in-dB response high-pass coupling, with a corner at approximately 0.016 GHz, Log slope of 23 mV/dB, intercept at 60 dBm at 0.9 GHz determines the lowest operating frequency. Therefore, the True integration function in control loop source can be dc grounded. Low power: 20 mW at 2.7 V, 38 mW at 5 V The AD8315 provides a voltage output, VAPC, that has the Power-down to 10.8 W voltage range and current drive to directly connect to most handset power amplifiers gain control pin. VAPC can swing APPLICATIONS from 250 mV above ground to within 200 mV below the supply Single, dual, and triple band mobile handset (GSM, DCS, EDGE) voltage. Load currents of up to 6 mA can be supported. Transmitter power control The setpoint control input is applied to the VSET pin and has GENERAL DESCRIPTION an operating range of 0.25 V to 1.4 V. The associated circuit The AD8315 is a complete low cost subsystem for the precise determines the slope and intercept of the linear-in-dB control of RF power amplifiers operating in the frequency range measurement system these are nominally 23 mV/dB and 0.1 GHz to 2.5 GHz and over a typical dynamic range of 50 dB. 60 dBm for a 50 termination (73 dBV) at 0.9 GHz. It is intended for use in cellular handsets and other battery- Further simplifying the application of the AD8315, the input operated wireless devices. The log amp technique provides a much resistance of the setpoint interface is over 100 M, and the bias wider measurement range and better accuracy than controllers current is typically 0.5 A. using diode detectors. In particular, the temperature stability is The AD8315 is available in MSOP and LFCSP packages and excellent over a specified range of 30C to +85C. consumes 8.5 mA from a 2.7 V to 5.5 V supply. When powered down, the sleep current is 4 A. FUNCTIONAL BLOCK DIAGRAM VPOS LOW NOISE OUTPUT LOW NOISE BAND GAP ENABLE GAIN BIAS ENBL REFERENCE DELAY VAPC 1.35 HI-Z DET DET DET DET DET LOW NOISE (25nV/ Hz) RAIL-TO-RAIL BUFFER RFIN FLTR 10dB 10dB 10dB 10dB VSET V-I 23mV/dB OFFSET INTERCEPT 250mV TO COMPN POSITIONING 1.4V = 50dB COMM Figure 1. Rev. D Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 19992016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 01520-001AD8315 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Practical Loop ............................................................................. 15 Applications ....................................................................................... 1 A Note About Power Equivalency ........................................... 15 General Description ......................................................................... 1 Basic Connections ...................................................................... 16 Functional Block Diagram .............................................................. 1 Range on VSET and RFIN ........................................................ 16 Revision History ............................................................................... 2 Transient Response .................................................................... 16 Specif icat ions ..................................................................................... 3 Mobile Handset Power Control Example ............................... 18 Absolute Maximum Ratings ............................................................ 5 Enable and Power-On ................................................................ 18 ESD Caution .................................................................................. 5 Input Coupling Options ............................................................ 19 Pin Configuration and Function Descriptions ............................. 6 Using the Chip Scale Package ................................................... 19 Typical Performance Characteristics ............................................. 7 Evaluation Board ........................................................................ 19 Theory of Operation ...................................................................... 12 Outline Dimensions ....................................................................... 21 Basic Theory ................................................................................ 12 Ordering Guide .......................................................................... 21 Controller-Mode Log Amps ..................................................... 13 Control Loop Dynamics ............................................................ 13 REVISION HISTORY 8/2016Rev. C to Rev. D Edit to Figure 3 ............................................................................... 10 Changes to Figure 2 and Table 4 ..................................................... 6 Edit to Equation 9 ........................................................................... 10 Added Figure 3 Renumbered Sequentially .................................. 6 Edit to Equation 10 ......................................................................... 10 Updated Outline Dimensions ....................................................... 21 Edit to Equation 11 ......................................................................... 10 Changes to Ordering Guide .......................................................... 21 Edits to Example section ............................................................... 10 Edit to Basic Connections Section ............................................... 12 6/2006Rev. B to Rev. C Edits to Input Coupling Options Section .................................... 14 Updated Format .................................................................. Universal Table III Becomes Table II ............................................................. 15 Changes to Ordering Guide .......................................................... 23 Table II Recommended Components Deleted ........................... 15 Using the Chip-Scale Package Section Added ............................ 15 1/2003Rev. 0 to Rev. B Edits to Evaluation Board Section ................................................ 15 Figure 12 Title Edited ..................................................................... 16 Edits to Product Description Section ............................................ 1 Edit to Functional Block Diagram ................................................. 1 Figure 13 Title Edited ..................................................................... 16 Edits to Specifications ...................................................................... 2 8-Lead Chip Scale Package (CP-8) Added .................................. 17 Edits to Absolute Maximum Ratings ............................................. 3 Updated Outline Dimensions ....................................................... 17 Ordering Guide Updated ................................................................. 3 TPC 9 Replaced with New Figure .................................................. 5 10/1999Revision 0: Initial Version Edits to TPC 27 ................................................................................. 8 Edit to Figure 1 .................................................................................. 9 Rev. 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