In motor drives, industrial power supplies, solar inverters, and battery management systems, isolated amplifiers are commonly used for shunt-resistor current sensing, high-side signal isolation, and common-mode interference suppression. This isolation enables safe and reliable signal transmission while significantly reducing measurement errors caused by ground-loop noise.

Texas Instruments (TI) AMC-series isolated amplifiers are widely used in industrial and power electronics designs. Among them, the AMC1100DUB, AMC1200BDUB, and AMC1301DWV are three highly representative models. While all three are designed for isolated current sensing, they have key differences in accuracy grades, immunity to interference, gain coefficients, and isolation safety ratings.

This article compares the key parameters and typical applications of these three devices, helping engineers quickly and accurately select the right component for their industrial control or power electronic systems.

Parameter Comparison

Application Analysis

• AMC1100DUB

The AMC1100DUB is the most widely used basic isolated amplifier in TI’s AMC series, renowned for its cost-effectiveness. Its design focuses on achieving reliable electrical isolation between the high-voltage side and the low-voltage control side while keeping the overall system BOM cost low.

Target Applications: Industrial motor drives, solar inverter current monitoring, and general-purpose switching power supply current sensing.

Key Features: Low cost and a mature design. It serves as the standard isolated sensing solution for general-purpose industrial power systems where extreme precision is not strictly required.

• AMC1200BDUB

Building upon the AMC1100, the AMC1200BDUB offers significantly improved linearity and higher common-mode transient immunity (CMTI), resulting in less waveform distortion.

Target Applications: Energy metering systems, industrial servo motor drives, precision power monitoring, and high-accuracy data acquisition systems.

Key Features: Its ultra-low nonlinearity error significantly improves the absolute accuracy of current sensing, making it highly advantageous in systems requiring precise closed-loop control and power calculations.

• AMC1301DWV

The AMC1301DWV is part of TI’s new generation of high-performance isolated amplifiers. It utilizes an advanced reinforced isolation structure, delivers a high bandwidth of up to 310 kHz, and features a drastically reduced offset voltage. Most importantly, it boasts exceptionally high transient immunity.

Target Applications: EV (Electric Vehicle) inverters, SiC/GaN wide-bandgap power conversion systems, and high-speed, high-voltage motor control systems.

Key Features: With a minimum CMTI of 140 kV/µs, it can effortlessly handle extreme high dv/dt interference generated by high-frequency switching nodes, making it well suited for high-power-density and high-voltage systems (e.g., 400V/800V buses).

Design Considerations

• Shunt Resistor Selection

All three isolated amplifiers are optimized for shunt-resistor current sensing, with an ideal linear input range typically spanning ±250 mV. During the design phase, select an appropriate resistance value based on the system’s maximum peak current:

Imax × Rshunt ≤ 250 mV

Exceeding this input voltage range will not only cause amplifier output saturation but also severely degrade the measurement accuracy of the ADC.

• Mind the Gain Differences

This is an easily overlooked detail during code porting or hardware replacement: the AMC1100 and AMC1200B have a fixed gain of 8 V/V, whereas the AMC1301 has a fixed gain of 8.2 V/V. When calculating the reconstructed ADC sampling values in the downstream MCU/DSP, the multiplication coefficient in the software algorithm must be adjusted accordingly. Failing to do so will directly introduce a fixed system error of approximately 2.5%.

• Device Matching in High dv/dt Systems

In SiC or GaN-based inverter systems, high-frequency switching at power nodes generates extremely high dv/dt. If the isolated amplifier’s CMTI is insufficient, the output will suffer from severe glitches or false triggers.

• • General industrial power systems (IGBT/MOSFET based): Choose AMC1100DUB.
  • High-Precision Closed-Loop Measurement: Choose AMC1200BDUB.
  • Wide-Bandgap (SiC/GaN) / EV Systems: AMC1301DWV is mandatory.
• PCB Layout and Package Creepage Distance

Because isolated amplifiers bridge a system’s high-voltage and low-voltage domains, PCB designs must strictly adhere to safety clearance distances. It is crucial to note that the AMC1100/1200 use the DUB package (standard SOIC-8), while the AMC1301 uses the DWV package (wide-body SOIC-8). The DWV wide-body package features wider pin spacing, specifically designed to meet the higher creepage and clearance requirements for “reinforced isolation.” Ensure the correct footprints are used when creating your PCB libraries to avoid confusion.

Device Summary

WIN SOURCE provides available inventory for TI’s AMC series isolated amplifiers, including AMC1100DUB, AMC1200BDUB, and AMC1301DWV. Engineers can quickly and accurately select the right components based on the system architectures and performance requirements discussed above. Visit WIN SOURCE to check real-time inventory and lead times, ensuring smooth progress for your R&D and mass production projects.