参数资料
| 型号： | AD620BRZ-RL |
| 厂商： | Analog Devices Inc |
| 文件页数： | 5/21页 |
| 文件大小： | 0K |
| 描述： | IC AMP INST LP LN 18MA 8SOIC |
| 设计资源： | Low Cost Programmable Gain Instrumentation Amplifier Circuit Using ADG1611 and AD620 (CN0146) |
| 标准包装： | 2,500 |
| 放大器类型： | 仪表 |
| 电路数： | 1 |
| 转换速率： | 1.2 V/µs |
| -3db带宽： | 1MHz |
| 电流 - 输入偏压： | 500pA |
| 电压 - 输入偏移： | 15µV |
| 电流 - 电源： | 900µA |
| 电流 - 输出 / 通道： | 18mA |
| 电压 - 电源，单路/双路(±)： | 4.6 V ~ 36 V，±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： | 带卷 (TR) |
AD620
Rev. H | Page 12 of 20
THEORY OF OPERATION
VB
–VS
A1
A2
A3
C2
RG
R1
R2
GAIN
SENSE
GAIN
SENSE
10k
I2
I1
10k
REF
10k
+IN
– IN
R4
400
OUTPUT
C1
Q2
Q1
00775-
0-
038
R3
400
+VS
20A
Figure 36. Simplified Schematic of AD620
The AD620 is a monolithic instrumentation amplifier based on
a modification of the classic three op amp approach. Absolute
value trimming allows the user to program gain accurately
(to 0.15% at G = 100) with only one resistor. Monolithic
construction and laser wafer trimming allow the tight matching
and tracking of circuit components, thus ensuring the high level
of performance inherent in this circuit.
The input transistors Q1 and Q2 provide a single differential-
pair bipolar input for high precision (Figure 36), yet offer 10×
lower input bias current thanks to Supereta processing.
Feedback through the Q1-A1-R1 loop and the Q2-A2-R2 loop
maintains constant collector current of the input devices Q1
and Q2, thereby impressing the input voltage across the external
gain setting resistor RG. This creates a differential gain from the
inputs to the A1/A2 outputs given by G = (R1 + R2)/RG + 1. The
unity-gain subtractor, A3, removes any common-mode signal,
yielding a single-ended output referred to the REF pin potential.
The value of RG also determines the transconductance of the
preamp stage. As RG is reduced for larger gains, the
transconductance increases asymptotically to that of the input
transistors. This has three important advantages: (a) Open-loop
gain is boosted for increasing programmed gain, thus reducing
gain related errors. (b) The gain-bandwidth product
(determined by C1 and C2 and the preamp transconductance)
increases with programmed gain, thus optimizing frequency
response. (c) The input voltage noise is reduced to a value of
9 nV/√Hz, determined mainly by the collector current and base
resistance of the input devices.
The internal gain resistors, R1 and R2, are trimmed to an
absolute value of 24.7 kΩ, allowing the gain to be programmed
accurately with a single external resistor.
The gain equation is then
1
4
.
49
+
Ω
=
G
R
k
G
1
4
.
49
Ω
=
G
k
R
G
Make vs. Buy: a Typical Bridge Application Error Budget
The AD620 offers improved performance over “homebrew”
three op amp IA designs, along with smaller size, fewer
components, and 10× lower supply current. In the typical
application, shown in Figure 37, a gain of 100 is required to
amplify a bridge output of 20 mV full-scale over the industrial
temperature range of 40°C to +85°C. Table 4 shows how to
calculate the effect various error sources have on circuit
accuracy.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD620SQ/883B | 功能描述:仪表放大器 IC LOW POWER IN-AMP IC 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 |
| AD621 | 制造商:AD 制造商全称:Analog Devices 功能描述:10 MHz, 20 V/レs, G = 1, 10, 100, 1000 i CMOS㈢ Programmable Gain Instrumentation Amplifier |
| AD621-00E | 功能描述:SENS MAG SW 20G CROS AXIS 8-MSOP 制造商:nve corp/sensor products 系列:AD 包装:管件 零件状态:有效 功能:全极开关 技术:霍尔效应 极化:任意一种 感应范围:±2.5mT 跳闸，±1.1mT 释放 测试条件:-40°C ~ 125°C 电压 - 电源:4.5 V ~ 30 V 电流 - 电源（最大值）:4.5mA 电流 - 输出（最大值）:20mA 输出类型:开路集电极 特性:- 工作温度:-40°C ~ 125°C（TA） 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商器件封装:8-MSOP 标准包装:1,000 |
| AD621-02E | 功能描述:SENSOR MAG SW 20G CROS AXS 8SOIC 制造商:nve corp/sensor products 系列:AD 包装:管件 零件状态:有效 功能:全极开关 技术:霍尔效应 极化:任意一种 感应范围:±2.5mT 跳闸，±1.1mT 释放 测试条件:-40°C ~ 125°C 电压 - 电源:4.5 V ~ 30 V 电流 - 电源（最大值）:4.5mA 电流 - 输出（最大值）:20mA 输出类型:开路集电极 特性:- 工作温度:-40°C ~ 125°C（TA） 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 供应商器件封装:8-SOIC 标准包装:1,000 |
| AD621A | 制造商:AD 制造商全称:Analog Devices 功能描述:Low Drift, Low Power Instrumentation Amplifier |
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