參數(shù)資料
型號(hào)： LOG2112AIDWRE4
廠商： TEXAS INSTRUMENTS INC
元件分類： 模擬運(yùn)算功能
英文描述： LOG OR ANTILOG AMPLIFIER, PDSO16
封裝： ROHS COMPLIANT, PLASTIC, MS-013AA, SOIC-16
文件頁(yè)數(shù)： 20/20頁(yè)
文件大小： 621K
代理商： LOG2112AIDWRE4
LOG112, 2112
9
SBOS246D
www.ti.com
FIGURE 8. Precision Current Inverter/Current Source.
1k
+5V
1.5k
1.5k
100k
10nA to 1mA
LOG112
10nA to 1mA
100k
100k
(+3.3V Back Bias)
+3.3V(1)
1/2
OPA2335
1/2
OPA2335
Photodiode
Pin 1 or Pin 14
100k
NOTE: (1) +3.3V bias is an arbitrary dc level < 5V that also
appears on the
IN through the op amp where it
applies a reverse bias to the photodiode.
VOLTAGE INPUTS
The LOG112 and LOG2112 give the best performances with
current inputs. Voltage inputs may be handled directly with
series resistors, but the dynamic input range is limited to
approximately three decades of input voltage by voltage
noise and offsets. The transfer function of Equation 13
applies to this configuration.
ACHIEVING HIGHER ACCURACY WITH HIGHER
INPUT CURRENTS
As input current to the LOG112 increases, output accuracy
degrades. For a 4.5mA input current on
±5V supplies and a
10mA input current on
±12V supplies, total output error can
be between 15% and 25%. Applying a common-mode volt-
age to VCM of at least +1V and up to 2.5V, brings the log
transistors out of saturation and reduces output error to
approximately 10%. To avoid forward biasing a photodiode,
return the cathode to the VCM pin, as shown in Figure 9. To
reverse bias the photodiode, apply a more positive voltage to
the cathode than the anode.
APPLICATION CIRCUITS
LOG RATIO
One of the more common uses of log ratio amplifiers is
to measure absorbance. See Figure 10 for a typical application.
Absorbance of the sample is A = log
λ
1/ λ1
(3)
If D1 and D2 are matched A ∝ (0.5V) logI1/I2
(4)
FIGURE 9. Extending Input Current Level and Improving Accuracy by Applying a Common-Mode Voltage.
A
2
A
1
Q
1
Q
2
C
I
1
V
REF – GND
V
O3
V+ = +5V
GND
LOG112
A
3
R
2
R
1
V
REF
100k
+2.5V
150k
R
REF
+IN3
V
LOGOUT
–IN3
V– = –5V
V
CM
I
2
V
REF
65
3
4
7
9
10
13
11
8
14
1
+1.5V
相關(guān)PDF資料
PDF描述
LOG112AIDE4 LOG OR ANTILOG AMPLIFIER, PDSO14
LOG112AID LOG OR ANTILOG AMPLIFIER, 1.4 MHz BAND WIDTH, PDSO14
LOG112AIDRE4 LOG OR ANTILOG AMPLIFIER, 1.4 MHz BAND WIDTH, PDSO14
LOS4301-2 1-OUTPUT 15 W AC-DC REG PWR SUPPLY MODULE
LOK4240-2RLD 1-OUTPUT 50 W AC-DC REG PWR SUPPLY MODULE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LOGIC 制造商:SALEAE LLC 功能描述:8 Channel Logic Analyzer
LOGIC PCBA 制造商:Misc 功能描述:
LOGIC SIZE 11 制造商:DEWALT 功能描述:DEWALT LOGIC SIZE 11
LOGIC SIZE 9 制造商:DEWALT 功能描述:DEWALT LOGIC SIZE 9
LOGIC1 制造商:BLUEBIRD ELECTRONICS 功能描述:LOGIC PROBE
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*