參數(shù)資料
型號(hào): LMC6032IN
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 運(yùn)動(dòng)控制電子
英文描述: CMOS Dual Operational Amplifier
中文描述: DUAL OP-AMP, 9000 uV OFFSET-MAX, 1.4 MHz BAND WIDTH, PDIP8
封裝: DIP-8
文件頁(yè)數(shù): 6/13頁(yè)
文件大?。?/td> 291K
代理商: LMC6032IN
Typical Performance Characteristics
V
S
=
±
7.5V, T
A
= 25C unless otherwise specified (Continued)
Note 13:
Avoid resistive loads of less than 500
, as they may cause instability.
Application Hints
AMPLIFIER TOPOLOGY
The topology chosen for the LMC6032, shown in Figure 1 is
unconventional (compared to general-purpose op amps) in
that the traditional unity-gain buffer output stage is not used;
instead, the output is taken directly from the output of the in-
tegrator, to allow a larger output swing. Since the buffer tra-
ditionally delivers the power to the load, while maintaining
high op amp gain and stability, and must withstand shorts to
either rail, these tasks now fall to the integrator.
As a result of these demands, the integrator is a compound
affair with an embedded gain stage that is doubly fed forward
(via C
and C
) by a dedicated unity-gain compensation
driver. In addition, the output portion of the integrator is a
push-pull configuration for delivering heavy loads. While
sinking current the whole amplifier path consists of three
gain stages with one stage fed forward, whereas while
sourcing the path contains four gain stages with two fed
forward.
The large signal voltage gain while sourcing is comparable
to traditional bipolar op amps, even with a 600
load. The
gain while sinking is higher than most CMOS op amps, due
to the additional gain stage; however, under heavy load
(600
) the gain will be reduced as indicated in the Electrical
Characteristics.
COMPENSATING INPUT CAPACITANCE
The high input resistance of the LMC6032 op amps allows
the use of large feedback and source resistor values without
losing gain accuracy due to loading. However, the circuit will
be especially sensitive to its layout when these large-value
resistors are used.
Every amplifier has some capacitance between each input
and AC ground, and also some differential capacitance be-
tween the inputs. When the feedback network around an
amplifier is resistive, this input capacitance (along with any
additional capacitance due to circuit board traces, the
socket, etc.) and the feedback resistors create a pole in the
feedback path. In the following General OperationalAmplifier
Circuit, Figure 2 the frequency of this pole is
where C
is the total capacitance at the inverting input, in-
cluding amplifier input capacitance and any stray capaci-
tance from the IC socket (if one is used), circuit board traces,
etc., and R
is the parallel combination of R
and R
. This
formula, as well as all formulae derived below, apply to in-
verting and non-inverting op-amp configurations.
When the feedback resistors are smaller than a few k
, the
frequency of the feedback pole will be quite high, since C
is
generally less than 10 pF. If the frequency of the feedback
pole is much higher than the “ideal” closed-loop bandwidth
(the nominal closed-loop bandwidth in the absence of C
),
the pole will have a negligible effect on stability, as it will add
only a small amount of phase shift.
However, if the feedback pole is less than approximately 6 to
10 times the “ideal” 3 dB frequency, a feedback capacitor,
C
, should be connected between the output and the invert-
ing input of the op amp. This condition can also be stated in
terms of the amplifier’s low-frequency noise gain: To main-
tain stability, a feedback capacitor will probably be needed if
Stability vs
Capacitive Load
DS011135-32
Stability vs
Capacitive Load
DS011135-33
DS011135-3
FIGURE 1. LMC6032 Circuit Topology (Each Amplifier)
www.national.com
6
相關(guān)PDF資料
PDF描述
LMC6061AIN Precision CMOS Single Micropower Operational Amplifier
LMC6061AMN Precision CMOS Single Micropower Operational Amplifier
LMC6061IM Precision CMOS Single Micropower Operational Amplifier
LMC6061IN Precision CMOS Single Micropower Operational Amplifier
LMC6061 Precision CMOS Single Micropower Operational Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LMC6032IN/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 CMOS Dual Op Amp RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMC6034 制造商:NSC 制造商全稱:National Semiconductor 功能描述:CMOS Quad Operational Amplifier
LMC6034IM 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMC6034IM/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMC6034IM/NOPB 制造商:Texas Instruments 功能描述:Operational Amplifier (Op-Amp) IC