AD641: 250 MHz, 44 dB Demodulating Logarithmic Amplifier
The AD641 is a 250 MHz, demodulating logarithmic amplifier with an accuracy of ±2.0 dB and 44 dB dynamic range. The AD641 uses a successive detection architecture to provide an output current ...More
AD641: 250 MHz, 44 dB Demodulating Logarithmic Amplifier
Product Description
The AD641 is a 250 MHz, demodulating logarithmic amplifier with an accuracy of ±2.0 dB and 44 dB dynamic range. The AD641 uses a successive detection architecture to provide an output current that is logarithmically proportional to its input voltage. The output current can be converted to a voltage using one of several on-chip resistors to select the slope. A single AD641 provides up to 44 dB of dynamic range at speeds up to 250 MHz, and two cascaded AD641s together can provide 58 dB of dynamic range at speeds up to 250 MHz. The AD641 is fully stable and well characterized over either the industrial or military temperature ranges.
The AD641 is not a logarithmic building block, but rather a complete logarithmic solution for compressing and measuring dynamic range signals. The AD641 is comprised of five stages and each stage has a full wave rectifier, whose current pends on the absolute value of its input voltage. The output of these stages are summed together to provide the demodulated output current scaled at 1 mA per decade (50 µA/dB).
Without utilizing the 10x input attenuator, log conformance of 2.0 dB is maintained over the input range -44 dBm to 0 dBm. The attenuator offers the most flexibility without significantly impacting performance.
The 250 MHz bandwidth and temperature stability make this product ideal for high speed signal power measurement in RF/IF systems. ECM/Radar and Communication applications are routinely in the 100 MHz-180 MHz range for power measurement. The bandwidth and accuracy, as well as dynamic range, make this part ideal for high speed, wide dynamic range signals.
The AD641 is offered in industrial (-40°C to +85°C) and military (-55°C to +125°C) package temperature ranges. Industrial versions are available in plastic DIP and PLCC; MIL versions are packaged in cerdip.
An evaluation board is available for this product and may be ordered using the following product number: AD641-EB.
Features
- Logarithmic Amplifier Performance
Usable to 250 MHz
44 dB Dynamic Range
±2.0 dB Log Conformance
37.5 mV/dB Voltage Output
Stable Slope and Intercepts - 2.0 nV/vHz Input Noise Voltage
- 50 µV Input Offset Voltage
- Low Power
±5 V Supply Operation
9 mA (+Vs), 35 mA (-Vs)
Quiescent Current - Onboard Resistors
- Onboard 10x Attenuator
- Dual Polarity Current Outputs
- Direct Coupled Differential Signal Path
Diagrams
- Enlarge
- 原理图符号和PCB封装
Pin Configuration Diagram for AD641
250 MHz, 44 dB Demodulating Logarithmic Amplifier
Pin Configuration Diagram for AD641
AD641 Model Options
| 产品型号 | 产品状态 | 封装 | Pins | 温度范围 | 报价* (100-499) |
Production** Availability |
ROHS Compliant | Samples Cart | Purchase Cart |
|---|---|---|---|---|---|---|---|---|---|
| 5962-9559801MRA | Prodn | 20 ld CerDIP | 20 | Mil | $ 259.96 | 12/05/2008 |
N
Material Declaration |
联络ADI | Add To Cart |
| AD641AN | Prodn | 20 ld PDIP | 20 | Ind | $ 37.96 | 12/05/2008 |
N
Material Declaration |
联络ADI | Add To Cart |
| AD641ANZ | Prodn | 20 ld PDIP | 20 | Ind | $ 36.31 | 12/05/2008 |
Y
Material Declaration |
联络ADI | Add To Cart |
| AD641AP | Prodn | 20 ld PLCC | 20 | Ind | $ 37.96 | 12/05/2008 |
N
Material Declaration |
联络ADI | Add To Cart |
| AD641AP-REEL7 | Prodn | 20 ld PLCC | 20 | Ind | $ 36.31 | 02/13/2009 |
N
Material Declaration |
联络ADI | Add To Cart |
| AD641APZ | Prodn | 20 ld PLCC | 20 | Ind | $ 36.31 | 12/05/2008 |
Y
Material Declaration |
联络ADI | Add To Cart |
Help
- 预发布:该产品型号尚未投入正式生产,但是可以提供样片。
- 生产:该产品型号目前已在生产,可以购买和索取样片。
- 停产前限时购买:该型号已经计划停产,但仍然可以在限定的时间内购买。
- 停产:该型号产品已经停产,不再提供。本表格中列出的其它型号产品仍可以供货(如果这些型号不处于停产状态)。
- 民用温度范围:0 ºC~+70 ºC
- 军用温度范围:-55ºC ~+125ºC
- 工业用温度范围:不同型号的产品的温度范围可能不同。欲了解更多信息,请查阅产品技术资料。
- 汽车工作温度范围:-40 ℃~ +125 ℃
Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.
*这里所列出的美国报价单仅供预算参考,指美元报价(规定订量的每片美元,美国离岸价),如有修改不再另行通知。由于地区关税、商业税、汇率及手续费原因,国际报价可能不同。对于特殊批量报价,请与您当地的ADI公司办事处或代理商联络。对于评估板和套件的报价是指一个单位价格。
**Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.

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