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參數(shù)資料
| 型號： | SA5230N |
| 廠商： | NXP SEMICONDUCTORS |
| 元件分類： | 運動控制電子 |
| 英文描述： | Low Voltage Operational Amplifier |
| 中文描述： | OP-AMP, 4000 uV OFFSET-MAX, 0.6 MHz BAND WIDTH, PDIP8 |
| 封裝： | 0.300 INCH, PLASTIC, DIP-8 |
| 文件頁數(shù)： | 10/17頁 |
| 文件大?。?/td> | 189K |
| 代理商： | SA5230N |
Philips Semiconductors
Product specification
NE/SA5230
Low voltage operational amplifier
1994 Aug 31
10
The NE5230 circuit shown in Figure 6 is a pseudo transistor
configuration. The inverting input is equivalent to the “base,” the
EE
and the non-inverting input meet is the “emitter,”
and the connection after the output diode meets the V
CC
pin is the
collector. The output diode is essential to keep the output from
saturating in this configuration. From here it can be seen that the
base and emitter form a voltage-follower and the voltage present at
R
C
must equal the input voltage present at the inverting input. Also,
the emitter and collector form a current-follower and the current
flowing through R
C
is equivalent to the current through R
L
and the
amplifier. This sets up the current loop. Therefore, the following
equation can be formulated for the working current transmission line.
The load current is:
I
L
=V
IN
/R
C
(2)
and proportional to the input voltage for a set R
C
. Also, the current is
constant no matter what load resistance is used while within the
operating bandwidth range of the op amp. When the NE5230’s
supply voltage falls past a certain point, the current cannot remain
constant. This is the “voltage compliance” and is very good for this
application because of the near rail output voltage. The equation
that determines the voltage compliance as well as the largest
possible load resistor for the NE5230 is as follows:
R
L max
=[V
remote supply
)-V
CC min
- V
IN max
]/I
L
(3)
Where V
CC min
is the worst-case power supply voltage
(approximately 1.8V) that will still keep the part operational. As an
example, when using a 15V remote power supply, a current sensing
resistor of 1
, and an input voltage (V
IN
) of 20mV, the output current
(I
L
) is 20mA. Furthermore, a load resistance of zero to
approximately 650
can be inserted in the loop without any change
in current when the bias current-control pin is tied to the negative
supply pin. The voltage drop across the load and line resistance will
not affect the NE5230 because it will operate down to 1.8V. With a
15V remote supply, the voltage available at the amplifier is still
enough to power it with the maximum 20mA output into the 650
load.
What this means is that several instruments, such as a chart
recorder, a meter, or a controller, as well as a long cable, can be
connected in series on the loop and still obtain accurate readings if
the total resistance does not exceed 650
. Furthermore, any
variation of resistance in this range will not change the output
current.
Any voltage output type transducer can be used, but one that does
not need external DC voltage or current excitation to limit the
maximum possible load resistance is preferable. Even this problem
can be surmounted if the supply power needed by the transducer is
compatible with the NE5230. The power goes up the line to the
transducer and amplifier while the transducer signal is sent back via
the current output of the NE5230 transconductance configuration.
The voltage range on the input can be changed for transducers that
produce a large output by simply increasing the current sense
resistor to get the corresponding 4 to 20mA output current. If a very
long line is used which causes high line resistance, a current
repeater could be inserted into the line. The same configuration of
Figure 6 can be used with exception of a resistor across the input
and line ground to convert the current back to voltage. Again, the
current sensing resistor will set up the transconductance and the
part will receive power from the line.
TEMPERATURE TRANSDUCER
A variation on the previous circuit makes use of the supply current
control pin. The voltage present at this pin is proportional to absolute
temperature (PTAT) because it is produced by the amplifier bias
current through an internal resistor divider in a PTAT cell. If the
control pin is connected to the input pin, the NE5230 itself can be
used as a temperature transducer. If the center tap of a resistive pot
is connected to the control pin with one side to ground and the other
to the inverting input, the voltage can be changed to give different
temperature versus output current conditions (see Figure 7). For
additional control, the output current is still proportional to the input
voltage differential divided by the current sense resistor.
When using the NE5230 as a temperature transducer, the thermal
considerations in the previous section must be kept in mind.
V
REMOTE
POWER
SUPPLY
NE5230
V
CC
V
EE
I
OUT
3
2
4
5
6
7
+
–
R
C
R
L
+
–
NOTES:
1. I
OUT
= V
IN/RC
2. R
L MAX
≈
VREMOTE
1.8V
VINMAX
IOUT
For R
C
= 1
IOUT
4mA
20mA
VIN
4mV
20mV
10
200
SL00256
Figure 7. NE5230 Remote Temperature Transducer Utilizing
4-20mA Current Transmission. This Application Shows the use
of the Accessibility of the PTAT Cell in the Device to Make the
Part, Itself, a Transducer
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| SA5232 | Matched dual high-performance low-voltage operational amplifier |
| SA5232D | Matched dual high-performance low-voltage operational amplifier |
| SA5232N | Matched dual high-performance low-voltage operational amplifier |
| SA532N | Low power dual operational amplifi |
| SA532 | Low power dual operational amplifi |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SA5230NG | 功能描述:運算放大器 - 運放 1.8V Single Rail to Rail Industrial Temp 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 |
| SA5232 | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Matched dual high-performance low-voltage operational amplifier |
| SA5232D | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Matched dual high-performance low-voltage operational amplifier |
| SA5232D,112 | 功能描述:運算放大器 - 運放 MATCHED DUAL LOW-VOLT 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 |
| SA5232D,118 | 功能描述:運算放大器 - 運放 MATCHED DUAL LOW-VOLT 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 |
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