800 MHz, Linear-in-dB VGA with AGC Detector Data Sheet AD8368 FEATURES FUNCTIONAL BLOCK DIAGRAM VPSO MODE VPSO VPSI VPSI VPSI VPSI VPSI Analog variable gain range: 12 dB to +22 dB 10 21 9 11 12 22 23 13 Linear-in-dB scaling: 37.5 dB/V ICOM 16 AD8368 3 dB bandwidth: 800 MHz VGAIN = 0.5 V OCOM 6 Integrated rms detector GAIN 1 GAIN INTERPOLATOR FIXED-GAIN OUTPUT 24 ENBL AMPLIFIER BUFFER P1dB: 16 dBm 140 MHz OCOM 7 8 OUTP Output IP3: 33 dBm 140 MHz g STAGES m 3 HPFL Noise figure at maximum gain: 9.5 dB 140 MHz 0dB 2dB 4dB 36dB 4 DECL Input and output impedances: 50 REF 19 INPT 14 DECL 50 Single-supply voltage from 4.5 V to 5.5 V 17 ICOM DECL 15 DECL 2 RoHS-compliant, 24-lead LFCSP X ICOM 18 ATTENUATOR LADDER + ICOM 20 2 5 APPLICATIONS DETO DETI Complete IF AGC amplifiers Figure 1. Gain trimming and leveling Cellular base stations Point-to-point radio links RF instrumentation GENERAL DESCRIPTION The AD8368 is a variable gain amplifier (VGA) with analog By connecting MODE to ground and using the on-board rms linear-in-dB gain control that can be used from low frequencies detector, the AD8368 can be configured as a complete to 800 MHz. Its excellent gain range, conformance, and flatness automatic gain control (AGC) system with RSSI. The output are attributed to the Analog Devices, Inc., X-AMP architecture, power is accurately leveled to the internal default setpoint of 63 mV rms (11 dBm referenced to 50 ), independent of the an innovative technique for implementing high performance variable gain control. waveform crest factor. Because the uncommitted detector input is available at DETI, the AGC loop can level the signal at The gain range of 12 dB to +22 dB is scaled accurately to the AD8368 output or at any other point in the signal chain 37.5 dB/V with excellent conformance error. The AD8368 has over a maximum input power range of 34 dB. Furthermore, the a 3 dB bandwidth of 800 MHz that is nominally independent setpoint level can be raised by dividing down the output signal of gain setting. At 140 MHz, the OIP3 is 33 dBm at maximum before applying it to the detector. gain. The output noise floor is 143 dBm/Hz, which corresponds to a 9.5 dB noise figure at maximum gain. The single-ended The AD8368 operates from a supply voltage of 4.5 V to 5.5 V and consumes 60 mA of current. It can be fully powered down input and output impedances are nominally 50 . to <3 mA by grounding the ENBL pin. The AD8368 is fabricated The gain of the AD8368 can be configured to be an increasing using the Analog Devices proprietary SiGe SOI complementary or decreasing function of the gain control voltage depending bipolar IC process. It is available in a 24-lead LFCSP and on whether the MODE pin is pulled to the positive supply or operates over the industrial temperature range of 40C to to ground, respectively. When MODE is pulled high, the +85C. Application boards are available upon request. AD8368 operates as a typical VGA with increasing gain. Rev. C 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 20062017 Analog Devices, Inc. All rights reserved. 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. Technical Support www.analog.com 05907-001AD8368* PRODUCT PAGE QUICK LINKS Last Content Update: 09/21/2017 COMPARABLE PARTS REFERENCE MATERIALS View a parametric search of comparable parts. Product Selection Guide RF Source Booklet EVALUATION KITS Variable Gain Amplifier Selection Table AD8368 Evaluation Board DESIGN RESOURCES DOCUMENTATION AD8368 Material Declaration Data Sheet PCN-PDN Information AD8368: 800 MHz, Linear-in-dB VGA with AGC Detector Quality And Reliability Data Sheet Symbols and Footprints TOOLS AND SIMULATIONS DISCUSSIONS ADIsimPLL View all AD8368 EngineerZone Discussions. ADIsimRF SAMPLE AND BUY REFERENCE DESIGNS Visit the product page to see pricing options. CN0072 CN0340 TECHNICAL SUPPORT CN0360 Submit a technical question or find your regional support number. DOCUMENT FEEDBACK Submit feedback for this data sheet. This page is dynamically generated by Analog Devices, Inc., and inserted into this data sheet. A dynamic change to the content on this page will not trigger a change to either the revision number or the content of the product data sheet. This dynamic page may be frequently modified.