參數(shù)資料
型號: MAX4206
廠商: Maxim Integrated Products, Inc.
元件分類: 運動控制電子
英文描述: Precision Transimpedance Logarithmic Amplifier with Over 5 Decades of Dynamic Range
中文描述: 高精度互阻對數(shù)放大器,動態(tài)范圍大于105
文件頁數(shù): 14/17頁
文件大?。?/td> 1241K
代理商: MAX4206
M
Precision Transimpedance Logarithmic
Amplifier with Over 5 Decades of Dynamic Range
14
______________________________________________________________________________________
Scale Factor
The scale factor, K, is the slope of the logarithmic output.
For the LOGV1 amplifier, K = 0.25V/decade. When oper-
ating from dual supplies, adjust the overall scale factor
for the MAX4206 using the uncommitted LOGV2 amplifi-
er and the following equation, which refers to Figure 6:
Select R
2
between 1k
and 100k
.
Design Example
Desired:
Dual-Supply Operation
Logarithmic intercept: 1μA
Overall scale factor = 1V/decade
Select R
1
= 10k
:
Measuring Optical Absorbance
A photodiode provides a convenient means of measur-
ing optical power, as diode current is proportional to
the incident optical power. Measure absolute optical
power using a single photodiode connected at LOGIIN,
with the MAX4206’s internal current reference driving
REFIIN. Alternatively, connect a photodiode to each of
the MAX4206’s logging inputs, LOGIIN and REFIIN, to
measure relative optical power (Figure 7).
In absorbance measurement instrumentation, a refer-
ence light source is split into two paths. The unfiltered
path is incident upon the photodiode of the reference
channel, REFIIN. The other path passes through a sam-
ple of interest, with the resulting filtered light incident on
the photodiode of the second channel, LOGIIN. The
MAX4206 outputs provide voltages proportional to the
log ratio of the two optical powers—an indicator of the
optical absorbance of the sample.
In wavelength-locking applications, often found in
fiberoptic communication modules, two photodiode cur-
rents provide a means of determining whether a given
optical channel is tuned to the desired optical frequency.
In this application, two bandpass optical filters with over-
lapping “skirts” precede each photodiode. With proper fil-
ter selection, the MAX4206 output can vary monotonically
(ideally linearly) with optical frequency.
R
k
V decade
1
0 25
.
k
2 10
40
×
=
/
R
V
μ
A
k
SET
=
=
0 5
.
10 1
50
R
R
K
.
2
1
0 25
=
MAX4206
V
EE
GND
REFIIN
LOGIIN
I
IN
CMVIN
CMVOUT
LOGV1
REFIOUT
REFISET
SCALE
LOGV2
OSADJ
REFVOUT
V
CC
V
CC
R
COMP
100
C
COMP
100pF
R
SET
500k
R
OS
0
R1
10k
R2
30k
0.1
μ
F
0.1
μ
F
V
OUT
0.1
μ
F
R
COMP
100
C
COMP
100pF
Figure
5. Single-Supply Typical Operating Circuit
MAX4206
V
EE
V
EE
GND
REFIIN
REFIOUT
LOGIIN
I
IN
REFISET
SCALE
LOGV2
LOGV1
CMVIN
CMVOUT
V
CC
V
CC
R
COMP
100
C
COMP
100pF
R
SET
50k
R1
10k
R2
40k
0.1
μ
F
0.1
μ
F
0.1
μ
F
V
OUT
R
100
C
COMP
100pF
OSADJ
REFVOUT
R4
R3
Figure
6. Dual-Supply Typical Operating Circuit
相關PDF資料
PDF描述
MAX4238AUT-T Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers
MAX4239AUT-T Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers
MAX4238 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers
MAX4238ASA Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers
MAX4239 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers
相關代理商/技術參數(shù)
參數(shù)描述
MAX4206ETE 功能描述:對數(shù)放大器 Transimpedance w/ 100Db Dynamic Range RoHS:否 制造商:Texas Instruments 通道數(shù)量:3 帶寬:3 dB 共模抑制比(最小值): 輸入補償電壓:+/- 7 mV 輸入電壓范圍(最大值):5.5 V 工作電源電壓:4.5 V to 5.5 V 電源電流:+/- 15 mA 工作溫度范圍:- 40 C to +85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
MAX4206ETE+ 功能描述:對數(shù)放大器 Transimpedance w/ 100Db Dynamic Range RoHS:否 制造商:Texas Instruments 通道數(shù)量:3 帶寬:3 dB 共模抑制比(最小值): 輸入補償電壓:+/- 7 mV 輸入電壓范圍(最大值):5.5 V 工作電源電壓:4.5 V to 5.5 V 電源電流:+/- 15 mA 工作溫度范圍:- 40 C to +85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
MAX4206ETE+T 功能描述:對數(shù)放大器 Transimpedance w/ 100Db Dynamic Range RoHS:否 制造商:Texas Instruments 通道數(shù)量:3 帶寬:3 dB 共模抑制比(最小值): 輸入補償電壓:+/- 7 mV 輸入電壓范圍(最大值):5.5 V 工作電源電壓:4.5 V to 5.5 V 電源電流:+/- 15 mA 工作溫度范圍:- 40 C to +85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
MAX4206ETE-T 功能描述:對數(shù)放大器 Transimpedance w/ 100Db Dynamic Range RoHS:否 制造商:Texas Instruments 通道數(shù)量:3 帶寬:3 dB 共模抑制比(最小值): 輸入補償電壓:+/- 7 mV 輸入電壓范圍(最大值):5.5 V 工作電源電壓:4.5 V to 5.5 V 電源電流:+/- 15 mA 工作溫度范圍:- 40 C to +85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
MAX4206EVKIT 功能描述:放大器 IC 開發(fā)工具 Transimpedance w/ 100Db Dynamic Range RoHS:否 制造商:International Rectifier 產(chǎn)品:Demonstration Boards 類型:Power Amplifiers 工具用于評估:IR4302 工作電源電壓:13 V to 23 V