參數(shù)資料
型號: OPA363IDR
廠商: Texas Instruments, Inc.
英文描述: LJT 46C 40#20 4#16 2#8(COAX) P
中文描述: 1.8,7MHz的,共模抑制比為90dB,單電源,軌到軌輸入/輸出運(yùn)算放大器
文件頁數(shù): 9/19頁
文件大?。?/td> 381K
代理商: OPA363IDR
OPA363, 2363, 364, 2364, 4364
SBOS259B
9
www.ti.com
ENABLE FUNCTION
The shutdown (enable) function of the OPA363 is referenced
to the negative supply voltage of the operational amplifier. A
logic level HIGH enables the op amp. A valid logic HIGH is
defined as voltage > 75% of the positive supply applied to the
enable pin. The valid logic HIGH signal can be as much as
5.5V above the negative supply, independent of the positive
supply voltage. A valid logic LOW is defined as < 0.8V above
the negative supply pin. If dual or split power supplies are
used, care should be taken to ensure logic input signals are
properly referred to the negative supply voltage. This pin
should be connected to a valid high or low voltage or driven,
not left open circuit.
The logic input is a high-impedance CMOS input. Dual op
amps are provided separate logic inputs. For battery-oper-
ated applications, this feature may be used to greatly reduce
the average current and extend battery life. The enable time
is 20
μ
s; disable time is 1
μ
s. When disabled, the output
assumes a high-impedance state. This allows the OPA363 to
be operated as a
gated
amplifier, or to have its output
multiplexed onto a common analog output bus.
CAPACITIVE LOAD
The OPA363 and OPA364 series op amps can drive a wide
range of capacitive loads. However, all op amps under
certain conditions may become unstable. Op amp configura-
tion, gain, and load value are just a few of the factors to
consider when determining stability. An op amp in unity-gain
configuration is the most susceptible to the effects of capaci-
tive load. The capacitive load reacts with the output resis-
tance of the op amp to create a pole in the small-signal
response, which degrades the phase margin.
In unity gain, the OPA363 and OPA364 series op amps
perform well with a pure capacitive load up to approximately
1000pF. The ESR (Equivalent Series Resistance) of the
loading capacitor may be sufficient to allow the OPA363 and
OPA364 to directly drive very large capacitive loads (> 1
μ
F).
Increasing gain enhances the amplifier
s ability to drive more
capacitance. See the typical characteristic
Small-Signal Over-
shoot vs Capacitive Load.
One method of improving capacitive load drive in the unity-
gain configuration is to insert a 10
to 20
resistor in series
with the output, as shown in Figure 3. This significantly
reduces ringing with large capacitive loads. However, if there
is a resistive load in parallel with the capacitive load, it
creates a voltage divider introducing a dc error at the output
and slightly reduces output swing. This error may be insignifi-
cant. For instance, with R
L
= 10k
and R
S
= 20
, there is
only about a 0.2% error at the output.
INPUT AND ESD PROTECTION
All OPA363 and OPA364 pins are static protected with
internal ESD protection diodes tied to the supplies. These
diodes will provide overdrive protection if the current is
externally limited to 10mA, as stated in the absolute maxi-
mum ratings and shown in Figure 4.
ACHIEVING OUTPUT SWING TO
THE OP AMP
S NEGATIVE RAIL
Some applications require an accurate output voltage swing
from 0V to a positive full-scale voltage. A good single supply op
amp may be able to swing within a few mV of single supply
ground, but as the output is driven toward 0V, the output stage
of the amplifier will prevent the output from reaching the
negative supply rail of the amplifier.
The output of the OPA363 or OPA364 can be made to swing to
ground, or slightly below, on a single supply power source. To do
so requires use of another resistor and an additional, more
negative power supply than the op amp
s negative supply. A
pulldown resistor may be connected between the output and the
additional negative supply to pull the output down below the value
that the output would otherwise achieve as shown in Figure 5.
FIGURE 3. Improving Capacitive Load Drive.
FIGURE 4. Input Current Protection.
FIGURE 5. OPA363 and OPA364 Swing to Ground.
10
to
20
V+
V
IN
V
OUT
R
S
R
L
C
L
OPAx363
OPAx364
V
OUT
R
P
= 10k
500
μ
A
OPA363
OPA364
V
IN
V+ = +5V
Op Amp
s
Negative
Supply
Grounded
V =
5V
(Additional
Negative Supply)
5k
OPAx363
10mA max
V+
V
IN
V
OUT
I
OVERLOAD
This technique will not work with all op amps. The output
stage of the OPA363 and OPA364 allows the output voltage
to be pulled below that of most op amps, if approximately
500
μ
A is maintained through the output stage. To calculate
the appropriate value load resistor and negative supply,
R
L
=
V/500
μ
A. The OPA363 and OPA364 have been
characterized to perform well under the described conditions,
maintaining excellent accuracy down to 0V and as low as
10mV. Limiting and nonlinearity occur below
10mV, with
linearity returning as the output is again driven above
10mV.
相關(guān)PDF資料
PDF描述
OPA641 Wideband Voltage Feedback Operational Amplifier(寬帶電壓反饋運(yùn)算放大器)
OPA644 Low Distortion Current Feedback Operational Amplifier(低失真電流反饋運(yùn)算放大器)
OPA646 Low Power, Wide Bandwidth Operational Amplifier(低功耗寬帶運(yùn)算放大器)
OPA654 Wide Bandwidth, High Output Current Operational Amplifier(寬帶大輸出電流運(yùn)算放大器)
OPA675JG Wideband Switched-Input OPERATIONAL AMPLIFIER
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
OPA363IDRG4 功能描述:運(yùn)算放大器 - 運(yùn)放 1.8V High CMR RRIO Op Amp w/Shutdown 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
OPA364 制造商:TI 制造商全稱:Texas Instruments 功能描述:1.8V, 7MHz, 90dB CMRR, SINGLE-SUPPLY, RAIL-TO-RAIL I/O OPERATIONAL AMPLIFIER
OPA364AID 功能描述:運(yùn)算放大器 - 運(yùn)放 1.8V High CMR RRIO 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
OPA364AIDBVR 功能描述:運(yùn)算放大器 - 運(yùn)放 1.8V High CMR RRIO 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
OPA364AIDBVRG4 功能描述:運(yùn)算放大器 - 運(yùn)放 1.8V High CMR RRIO 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