Datasheet > AD8361_1

AD8361_1

更新时间： 2022-10-09 09:19:58

品牌	Logo	应用领域
亚德诺 - ADI		/
页数	文件大小	规格书
24页	853K
描述
LF to 2.5 GHz TruPwr? Detector

阅读下载

获取价格

数据手册

如果您发现信息不准确，欢迎纠错

AD8361_1 数据手册

AD8361

2.5 GHz. However, it is necessary to calibrate for a given

application to accommodate for the change in conversion gain

at higher frequencies.

One of the AD8361s (U2) has a net gain of about 14 dB

preceding it and therefore operates most accurately at low input

signal levels. This is referred to as the weak signal path. U4, on

the other hand, does not have the added gain and provides

accurate response at high levels. The output of U2 is attenuated

by R1 in order to cancel the effect of U2’s preceding gain so that

the slope of the transfer function (as seen at the slider of R1) is

the same as that of U4 by itself.

Dynamic Range Extension for the AD8361

The accurate measurement range of the AD8361 is limited by

internal dc offsets for small input signals and by square law

conformance errors for large signals. The measurement range

may be extended by using two devices operating at different

signal levels and then choosing only the output of the device

that provides accurate results at the prevailing input level.

The circuit comprising U3, U5, and U6 is a crossfader, in which

the relative gains of the two inputs are determined by the output

currents of a fuzzy comparator made from Q1 and Q2.

Assuming that the slider of R2 is at 2.5 V dc, the fuzzy

comparator commands full weighting of the weak signal path

when the output of U2 is below about 2.0 V dc, and full

weighting of the strong signal path when the output of U3

exceeds about 3.0 V dc. U3 and U5 are OTAs (operational

transconductance amplifiers).

Figure 60 depicts an implementation of this idea. In this circuit,

the selection of the output is made gradually over an input level

range of about 3 dB in order to minimize the impact of

imperfect matching of the transfer functions of the two

AD8361s. Such a mismatch typically arises because of the

variation of the gain of the RF preamplifier U1 and both the

gain and slope variations of the AD8361s with temperature.

270Ω

0.01µF

12V

RFC

+12V

16kΩ

100pF

AD8361

5kΩ

6dB

PA D

ERA-3

20dB

CA3080

0.1µF

68Ω

8.2nF

12V

–5V

20kΩ

100Ω

1kΩ

AD820

OUT

20kΩ

10kΩ

6dB

SPLITTER

INPUT

2N3906 2N3906

0.01µF

+12V

20kΩ

12kΩ

100pF

AD8361

CA3080

0.1µF

68Ω

1MΩ

–5V

+5V

–5V

10kΩ

Figure 60. Range Extender Application

Rev. C | Page 19 of 24

1...16 17 181920 21 22...24

下载PDF

与AD8361_1相关器件

型号	品牌	描述	获取价格	数据表
AD8361_15	ADI	LF to 2.5 GHz TruPwr Detector	获取价格
AD8361ARM	ADI	LF to 2.5 GHz TruPwr⑩ Detector	获取价格
AD8361ARM-REEL	ADI	LF to 2.5 GHz TruPwr⑩ Detector	获取价格
AD8361ARM-REEL7	ADI	LF to 2.5 GHz TruPwr⑩ Detector	获取价格
AD8361ARMZ	ADI	LF to 2.5 GHz TruPwr Detector	获取价格
AD8361ARMZ1	ADI	LF to 2.5 GHz TruPwr? Detector	获取价格