参数资料
| 型号： | AD621BRZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 5/16页 |
| 文件大小： | 0K |
| 描述： | IC AMP INST LDRIFT LP 18MA 8SOIC |
| 产品培训模块： | Instrumentation Amplifiers Performance |
| 标准包装： | 1 |
| 放大器类型： | 仪表 |
| 电路数： | 1 |
| 转换速率： | 1.2 V/µs |
| -3db带宽： | 800kHz |
| 电流 - 输入偏压： | 500pA |
| 电压 - 输入偏移： | 50µV |
| 电流 - 电源： | 900µA |
| 电流 - 输出 / 通道： | 18mA |
| 电压 - 电源，单路/双路(±)： | ±2.3 V ~ 18 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 供应商设备封装： | 8-SO |
| 包装： | 管件 |
| 产品目录页面： | 770 (CN2011-ZH PDF) |
AD621
REV. B
–13–
Precision V-I Converter
The AD621 along with another op amp and two resistors make
a precision current source (Figure 9). The op amp buffers the
reference terminal to maintain good CMR. The output voltage
VX of the AD621 appears across R1 which converts it to a cur-
rent. This current less only the input bias current of the op amp
then flows out to the load.
+VS
VIN–
VIN+
AD621
+VX–
R1
IL
AD705
LOAD
–VS
IL =
VX
R1
(VIN+) – (VIN–) G
R1
=
Figure 9. Precision Voltage to Current Converter
(Operates on 1.8 mA,
±3 V)
INPUT AND OUTPUT OFFSET VOLTAGE
The AD621 is fully specified for total input errors at gains of 10
and 100. That is, effects of all error sources within the AD621
are properly included in the guaranteed input error specs, elimi-
nating the need for separate error calculation.
Total Error RTI = Input Error + (Output Error/G)
Total Error RTO = (Input Error
× G) + Output Error
REFERENCE TERMINAL
Although usually grounded, the reference terminal may be used
to offset the output of the AD621. This is useful when the load
is “floating” or does not share a ground with the rest of the system.
It also provides a direct means of injecting a precise offset.
Another benefit of having a reference terminal is that it can be
quite effective in eliminating ground loops and noise in a circuit
or system.
VOL
+VS
AD621
VOUT
–VS
VOL
RP
GAIN = 10 OR 100
Figure 10. Input Overload Protection
INPUT OVERLOAD CONSIDERATIONS
Failure of a transducer, faults on input lines, or power supply
sequencing can subject the inputs of an instrumentation ampli-
fier to voltages well beyond their linear range, or even the supply
voltage, so it is essential that the amplifier handle these over-
loads without being damaged.
The AD621 will safely withstand continuous input overloads of
±3.0 volts (±6.0 mA). This is true for gains of 10 and 100, with
power on or off.
The inputs of the AD621 are protected by high current capacity
dielectrically isolated 400
thin-film resistors R3 and R4 (Fig-
ure 3) and by diodes which protect the input transistors Q1 and
Q2 from reverse breakdown. If reverse breakdown occurred, there
would be a permanent increase in the amplifier’s input current.
The input overload capability of the AD621 can be easily increased
while only slightly degrading the noise, common-mode rejection
and offset drift of the device by adding external resistors in series
with the amplifier’s inputs as shown in Figure 10.
Table II summarizes the overload voltages and total input
noise for a range of range of r values. Note that a 2 k
resis-
tor in series with each input will protect the AD621 from a
±15 volt continuous overload, while only increasing input noise
to 13 nV
√Hz—about the same level as would be expected from
a typical unprotected 3 op amp in amp.
Table II. Input Overload Protection vs. Value of Resistor RP
Total Input Noise
Maximum Continuous
Value of
in nV
√Hz @ 1 kHz
Overload Voltage, VOL
Resistor RP G = 10
G = 100
In Volts
014
9
3
499
14
10
6
1.00 k
14
11
9
2.00 k
15
13
15
3.01 k
*
16
14
21
4.99 k
*
17
16
33
*1/4 watt, 1% metal-film resistor. All others are 1/8 watt, 1% RN55
or equivalent.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD621BRZ | 制造商:Analog Devices 功能描述:IC, INSTRUMENT AMP, 800KHZ, 130DB SOIC-8 |
| AD621BRZ-R7 | 功能描述:IC AMP INST LDRIFT LP 18MA 8SOIC RoHS:是 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:2,500 系列:Excalibur™ 放大器类型:J-FET 电路数:1 输出类型:- 转换速率:45 V/µs 增益带宽积:10MHz -3db带宽:- 电流 - 输入偏压:20pA 电压 - 输入偏移:490µV 电流 - 电源:1.7mA 电流 - 输出 / 通道:48mA 电压 - 电源，单路/双路(±):4.5 V ~ 38 V，±2.25 V ~ 19 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 供应商设备封装:8-SOIC 包装:带卷 (TR) |
| AD621BRZ-RL | 功能描述:IC AMP INST LDRIFT LP 18MA 8SOIC RoHS:是 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:2,500 系列:Excalibur™ 放大器类型:J-FET 电路数:1 输出类型:- 转换速率:45 V/µs 增益带宽积:10MHz -3db带宽:- 电流 - 输入偏压:20pA 电压 - 输入偏移:490µV 电流 - 电源:1.7mA 电流 - 输出 / 通道:48mA 电压 - 电源，单路/双路(±):4.5 V ~ 38 V，±2.25 V ~ 19 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 供应商设备封装:8-SOIC 包装:带卷 (TR) |
| AD621S | 制造商:AD 制造商全称:Analog Devices 功能描述:Low Drift, Low Power Instrumentation Amplifier |
| AD621SQ/883B | 功能描述:仪表放大器 LOW DRIFT LOW POWER INAMP RoHS:否 制造商:Texas Instruments 通道数量: 输入补偿电压:150 V 可用增益调整: 最大输入电阻:10 kOhms 共模抑制比（最小值）:88 dB 工作电源电压:2.7 V to 36 V 电源电流:200 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:MSOP-8 封装:Bulk |
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