- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379896 > CLC425AJE (COMLINEAR CORP) Ultra Low Noise Wideband Op Amp PDF資料下載
參數(shù)資料
| 型號(hào)： | CLC425AJE |
| 廠商： | COMLINEAR CORP |
| 元件分類： | 運(yùn)動(dòng)控制電子 |
| 英文描述： | Ultra Low Noise Wideband Op Amp |
| 中文描述： | OP-AMP, 800 uV OFFSET-MAX, PDSO8 |
| 文件頁數(shù)： | 6/9頁 |
| 文件大小： | 1275K |
| 代理商： | CLC425AJE |
As seen in Figure 5, e
ni
is dominated by the intrinsic
voltage noise (e
n
) of the amplifier for equivalent source
resistances below 33.5
. Between 33.5
and 6.43k
,
e
ni
is dominated by the thermal noise (
e
the external resistors. Above 6.43k
, e
ni
is dominated by
the amplifier's current noise (
2i R
which the CLC425's voltage noise and current noise
contribute equally occurs for R
seq
=464
(i.e.
e
As an example, configured with a gain of +20V/V giving
a -3dB of 90MHz and driven from an R
seq
=25
, the
CLC425 produces a total equivalent input noise voltage
(
e
1.57 90MHz
) of 16.5
μ
V
rms
.
4 TR
k
seq
=
) of
seq
). The point at
2i
/
).
ni
Figure 5: Voltage Noise Density vs. Source Resistance
If bias current cancellation is not a requirement, then
R
f
||R
g
does not need to equal R
seq
. In this case, according
to Equation 1, R
f
||R
g
should be as low as possible in
order to minimize noise. Results similar to Equation 1
are obtained for the inverting configuration of Figure 2 if
R
seq
is replaced by R
b
and R
g
is replaced by R
g
+R
s
. With
these substitutions, Equation 1 will yield an e
ni
refered to
the non-inverting input. Refering e
ni
to the inverting input
is easily accomplished by multiplying e
ni
by the ratio of
non-inverting to inverting gains.
Noise Figure
Noise Figure (NF) is a measure of the noise degradation
caused by an amplifier.
The Noise Figure formula is shown in Equation 3. The
addition of a terminating resistor R
T
, reduces the
external thermal noise but increases the resulting NF.
The NF is increased because R
T
reduces the input signal
amplitude thus reducing the input SNR.
R
seq
= R
s
for Unterminated Systems
R
seq
= R
s
II R
T
for Terminated Systems
Equation 3: Noise Figure Equation
The noise figure is related to the equivalent source
resistance (R
seq
) and the parallel combination of R
f
and
R
g
. To minimize noise figure, the following steps are
recommended:
Minimize R
f
||R
g
Choose the optimum R
s
(R
OPT
)
R
OPT
is the point at which the NF curve reaches a
minimum and is approximated by:
R
OPT
(e
n
/i
n
)
Figure 6 is a plot of NF vs R
s
with R
f
||R
g
= 9.09 (A
v
= +10).
The NF curves for both Unterminated and Terminated
systems are shown. The Terminated curve assumes R
s
= R
T
. The table indicates the NF for various source
resistances including R
s
= R
OPT
.
Figure 6: Noise Figure vs Source Resistance
Supply Current Adjustment
The CLC425's supply current can be externally adjusted
downward from its nominal value by adding an optional
resistor (R
p
) between pin 8 and the negative supply as
shown in Figure 7. Several of the plots found within the plot
pages demonstrate the CLC425’s behavior at different
supply currents. The plot labeled “I
cc
vs. R
p
” provides the
means for selecting R
p
and shows the result of standard IC
process variation which is bounded by the 25°C curve.
Figure 7: External Supply Current Adjustment
Non-Inverting Gains Less Than 10V/V
Using the CLC425 at lower non-inverting gains requires
external compensation such as the shunt compensation
as shown in Figure 8. The quiescent supply current must
also be reduced to 5mA with R
p
for stability. The com-
pensation capacitors are chosen to reduce frequency
response peaking to less than 1dB. The plot in the
"Typical Performance" section labeled “Differential Gain
and Phase” shows the video performance of the CLC425
with this compensation circuitry.
3
2
4
7
6
8
+V
cc
-V
cc
V
out
R
p
CLC425
NF
10LOG
S / N
S / N
10LOG
e
e
i
o
ni
2
t
2
=
=
NF
10LOG
e
i
R
R ||R
4kTR
4kT R ||R
4kTR
n
2
n
2
seq
g
2
seq
g
seq
=
+
+
(
)
+
)
http://www.national.com
6
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| CLC425ALC | Faceplate; Enclosure Color:Off White RoHS Compliant: Yes |
| CLC425 | Ultra Low Noise Wideband Op Amp |
| CLC425AMC | Ultra Low Noise Wideband Op Amp |
| CLC425AJM5 | Ultra Low Noise Wideband Op Amp |
| CLC425A8B | Ultra Low Noise Wideband Op Amp |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| CLC425AJE-TR13 | 制造商:ROCHESTER 制造商全稱:ROCHESTER 功能描述:ULTRA LOW NOISE OP AMP with a wide variety of applications Operational Amplifier |
| CLC425AJM5 | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| CLC425AJM5X | 制造商:ROCHESTER 制造商全稱:ROCHESTER 功能描述:ULTRA LOW NOISE OP AMP with a wide variety of applications Operational Amplifier |
| CLC425AJ-MLS | 制造商:ROCHESTER 制造商全稱:ROCHESTER 功能描述:ULTRA LOW NOISE OP AMP with a wide variety of applications Operational Amplifier |
| CLC425AJP | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Ultra Low Noise Wideband Op Amp |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。