AD8318
1 MHz TO 8 GHz, 70 dB Logarithmic Detector/Controller
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Overview
Features and Benefits
- 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
- Download AD8318-EP data sheet (pdf)
- V62/12665 DSCC Drawing Number
Product Details
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 unprecedented 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.
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, VOUT, which 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 temperature range of –40°C to +85°C.
Applications
- RF transmitter PA setpoint control and level monitoring
- RSSI measurement in base stations, WLAN, WiMAX, and radars
Product Categories
Markets and Technologies
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Documentation & Resources
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FAQs7/26/2017
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Design the Best Front End for UHF Partial Discharge Online Monitoring Systems10/1/2021
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Noise Figure and Logarithmic Amplifiers [The Wit and Wisdom of Dr. Leif—6]6/1/2008 Analog Dialogue
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Measuring the RF Power in CDMA2000 and W-CDMA High Power Amplifiers (HPAs)11/1/2005
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Detecting Fast RF Bursts using Log Amps12/1/2002
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Make Precise Base-Station Power Measurements11/2/2002
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Measurement and Control of RF Power (Part III)2/9/2001
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Measurement and Control of RF Power (Part II)12/1/2000
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Measurement and Control of RF Power (Part I)10/19/2000
Software & Systems Requirements
Tools & Simulations
Design Tools
ADIsimRF
ADIsimRF is an easy-to-use RF signal chain calculator. Cascaded gain, noise, distortion and power consumption can be calculated, plotted and exported for signal chains with up to 50 stages. ADIsimRF also includes an extensive data base of device models for ADI’s RF and mixed signal components.
ADIsimPLL™
ADIsimPLL enables the rapid and reliable evaluation of new high performance PLL products from ADI. It is the most comprehensive PLL Synthesizer design and simulation tool available today. Simulations performed include all key non-linear effects that are significant in affecting PLL performance. ADIsimPLL removes at least one iteration from the design process, thereby speeding the design- to-market.
Reference Designs (1)
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
| Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| AD8318ACPZ-R2 | Material Declaration | Reliability Data | 16-Lead LFCSP (4mm x 4mm × 0.75 w/ EP) | |
| AD8318ACPZ-REEL7 | Material Declaration | Reliability Data | 16-Lead LFCSP (4mm x 4mm × 0.75 w/ EP) | |
| AD8318ACPZ-WP | Material Declaration | Reliability Data | 16-Lead LFCSP (4mm x 4mm × 0.75 w/ EP) | |
| AD8318SCPZ-EP-R2 | Material Declaration | Reliability Data | 16-Lead LFCSP (4mm x 4mm) | |
| AD8318SCPZ-EP-RL7 | Material Declaration | Reliability Data | 16-Lead LFCSP (4mm x 4mm) | |
| AD8318SCPZ-EP-WP | Material Declaration | Reliability Data | 16-Lead LFCSP (4mm x 4mm) | |
| Wafer Fabrication Data |
PCN-PDN Information
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Support & Discussions
AD8318 Discussions
RE: AD8318 detector output voltage when there is no signal?
15 week(s) ago in RF and Microwave
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.