原创 AD623: 单电源、轨到轨、低成本仪表放大器

    AD623:  单电源、轨到轨、低成本仪表放大器
    AD623是一款集成式单电源仪表放大器，采用3 V至12 V电源供电时提供轨到轨输出摆幅。它可以通过单一增益设置电阻进行编程，并遵照8引脚工业标准引脚排列配置，赋予用户出众的灵活性。不接外部电阻时，AD623采用单位增益配置(G = 1)；连接外部电阻时，AD623可通过编程实现最高增益1000。

    AD623具有优异的交流共模抑制比(CMRR)，并且随着增益提高而增大，因此可确保误差极小。由于CMRR在最高200 Hz时仍然保持稳定，因此线路噪声和线路谐波均得到抑制。AD623具有宽输入共模范围，可以放大共模电压低于地电压150 mV的信号。虽然AD623设计针对单电源供电进行了优化，但采用双电源(±2.5 V至±6.0 V)供电时，AD623仍能提供出色的性能。

    低功耗(3 V电源时为1.5 mW)、宽电源电压范围以及轨到轨输出摆幅使AD623成为电池供电应用的理想之选。采用低电源电压工作时，轨到轨输出级可以使动态范围达到最大。AD623可以取代分立式仪表放大器设计，在极小的空间中提供出色的线性度、温度稳定性和可靠性。

    应用

低功耗医疗仪器
传感器接口
热电偶放大器
工业过程控制
差动放大器
低功耗数据采集
 

易于使用
具有比分立式设计更高的性能
单电源与双电源供电
轨到轨输出摆幅
输入电压范围达到地电压以下150 mV(单电源)
低功耗，最大电源电流为550 μA
通过一个外部电阻设置增益，
增益范围：1(无电阻)至1000
高精度直流性能
增益精度：0.10% (G = 1)
增益精度：0.35% (G >1)
增益漂移：10 ppm (G = 1)
输入偏置电流：25 nA(最大值)
出色的交流特性
CMRR：90 dB (最小值,G = 10)；CMRR：70 dB(最小值,G = 1、60 Hz、1kΩ非均衡电源)
带宽：800 kHz (G = 1)
0.01%建立时间：20 μs (G = 10)
噪声
折合到输入端噪声：35 nV/√Hz(1 kHz、G = 1)
 

The AD623 is an integrated single-supply instrumentation amplifier that delivers rail-to-rail output swing on a 3 V to 12 V supply. The AD623 offers superior user flexibility by allowing single gain set resistor programming and by conforming to the 8-lead industry standard pinout configuration. With no external resistor, the AD623 is configured for unity gain (G = 1), and with an external resistor, the AD623 can be programmed for gains up to 1000.

The AD623 holds errors to a minimum by providing superior ac CMRR that increases with increasing gain. Line noise, as well as line harmonics, are rejected because the CMRR remains constant up to 200 Hz. The AD623 has a wide input common-mode range and can amplify signals that have a common-mode voltage 150 mV below ground. Although the design of the AD623 was optimized to operate from a single supply, the AD623 still provides superior performance when operated from a dual voltage supply (±2.5 V to ±6.0 V).

Low power consumption (1.5 mW at 3 V), wide supply voltage range, and rail-to-rail output swing make the AD623 ideal for battery-powered applications. The rail-to-rail output stage maximizes the dynamic range when operating from low supply voltages. The AD623 replaces discrete instrumentation amplifier designs and offers superior linearity, temperature stability, and reliability in a minimum of space.

Applications

Low power medical instrumentation
Transducer interfaces
Thermocouple amplifiers
Industrial process controls
Difference amplifiers
Low power data acquisition
 

Easy to use

Higher performance than discrete design
Single-supply and dual-supply operation
Rail-to-rail output swing
Input voltage range extends 150 mV below ground (single supply)
Low power, 550 μA max supply current
Gain set with one external resistor, gain range 1 (no resistor) to 1,000
High Accuracy DC Performance
0.10% gain accuracy (G = 1)
0.35% gain accuracy (G >1)
10 ppm gain drift (G = 1)
25 nA maximum input bias current
Excellent AC Specifications
90 dB minimum CMRR (G = 10); 70 dB minimum CMRR (G = 1) at 60 Hz, 1kΩ source imbalance)
800 kHz bandwidth (G = 1)
20 μs settling time to 0.01% (G = 10)
Noise
35 nV/√vHz RTI noise @ 1 kHz (G = 1)