The AMC1336DWVR is a precision isolated delta-sigma modulator from Texas Instruments designed specifically for voltage sensing in high-voltage systems. Unlike conventional ADCs that directly digitize analog signals, this device produces a 1-bit digital bitstream whose density encodes the analog input value, with the output galvanically isolated from the input by a capacitive double isolation barrier. This architecture, combined with a unique ±1-V bipolar input range and exceptionally high input resistance of 1.5 GΩ, makes the AMC1336DWVR ideally suited for direct connection to resistive voltage dividers in motor drives, traction inverters, onboard chargers, and industrial power conversion systems.

Capacitive Double Isolation Barrier

The AMC1336DWVR separates its input and output circuitry through a silicon dioxide (SiO₂) based capacitive double isolation barrier that is highly resistant to magnetic interference. Unlike optical isolation, which can degrade over time and is sensitive to temperature, or magnetic isolation, which is susceptible to external field interference, the capacitive barrier provides stable, long-term isolation performance with excellent common-mode transient immunity.

Reinforced Isolation Ratings

The isolation barrier is certified to provide reinforced isolation of up to 8000 V_PEAK according to DIN VDE V 0884-11: 2017-01 standards. Additionally, the device meets UL1577 requirements for 5700 V_RMS isolation for one minute and complies with the IEC 62368-1 end equipment standard. These certifications allow system designers to meet safety requirements for equipment operating from high-voltage rails without additional isolation components, reducing bill-of-materials cost and board space.

Transient Immunity

Common-mode transient immunity is specified at 115 kV/µs typical, ensuring that the digital output remains valid even in the presence of the fast voltage transients characteristic of switching power converters and motor drives.

Wide Bipolar Input Range

The AMC1336DWVR accepts a differential input voltage range of ±1 V, a significantly wider range than the ±250-mV or ±50-mV inputs typical of isolated modulators designed for shunt-based current sensing. This bipolar capability enables direct measurement of both positive and negative voltages in the system, eliminating the need for level-shifting circuitry when monitoring AC phase voltages or DC-link voltages that swing symmetrically around a reference point.

High Input Impedance for Direct Divider Connection

The 1.5-GΩ typical input resistance is a defining characteristic of the device. In high-voltage sensing applications, resistive dividers are used to scale dangerous voltages down to levels that semiconductor devices can safely process. A divider with a total resistance of several megohms is common. The AMC1336DWVR's high input impedance ensures that the divider's output voltage is not significantly loaded, preserving measurement accuracy without requiring an intermediate buffer amplifier.

Offset and Gain Accuracy

The AMC1336DWVR delivers excellent DC accuracy with a maximum offset error of ±0.5 mV and offset drift of ±4 µV/°C. Gain error is limited to ±0.25% maximum, with gain drift specified at ±40 ppm/°C maximum. These specifications are maintained across the extended industrial temperature range of –40°C to +125°C, ensuring reliable performance in the thermally demanding environments typical of motor control cabinets and power electronics enclosures.

Effective Resolution and Dynamic Range

When paired with a suitable digital decimation filter—such as those integrated into the TMS320F28004x, TMS320F2807x, or TMS320F2837x microcontroller families—the AMC1336DWVR achieves 16 bits of resolution with an 87-dB dynamic range at a data rate of 82 kSPS. This level of performance is sufficient for the voltage feedback loops in field-oriented motor control, where accurate phase voltage reconstruction is essential for precise torque regulation.

Traction Inverter Phase Voltage Sensing

In electric vehicle traction inverters, accurate measurement of the three-phase output voltages is required for field-oriented control and fault detection. The AMC1336DWVR's ±1-V input range and high input impedance allow it to be connected directly to a resistive divider spanning the inverter's high-voltage DC bus, while the reinforced isolation barrier protects the low-voltage control electronics from the traction voltage. The bitstream output is decimated by the microcontroller's integrated delta-sigma filter, eliminating the need for an external ADC.

Onboard Charger DC-Link Monitoring

Onboard chargers (OBCs) in electric vehicles require precise monitoring of the DC-link voltage for battery charging control and protection. The AMC1336DWVR's bipolar input capability enables measurement of voltages that may swing below ground during transient conditions, while the isolation barrier maintains the required separation between the high-voltage battery system and the vehicle's low-voltage control network.

Industrial Motor Drive Voltage Feedback

In industrial servo drives and variable-frequency drives, the AMC1336DWVR provides isolated voltage feedback for the motor control loop. Its high common-mode transient immunity ensures reliable operation in the presence of the fast switching transients generated by IGBT or SiC power stages. The device's ability to operate from either 3.3-V or 5-V high-side supplies simplifies interfacing with existing gate driver power architectures.

Renewable Energy and Grid-Tied Inverters

Solar inverters and energy storage systems require isolated voltage sensing for DC bus monitoring and grid synchronization. The AMC1336DWVR's reinforced isolation certifications and wide temperature range make it suitable for the harsh environmental conditions encountered in outdoor renewable energy installations.

The AMC1336DWVR is distinguished from its family members—the AMC1303 and AMC1306—primarily by its input voltage range. While the AMC1306 series is optimized for ±250-mV shunt-based current sensing, the AMC1336DWVR's ±1-V input and high input impedance specifically target voltage sensing through resistive dividers. Designers should select the device variant whose input range best matches the sensing element: current shunts for the AMC1306, voltage dividers for the AMC1336.

Texas Instruments provides the AMC1336EVM evaluation module, a fully assembled platform for characterizing the modulator's performance. The EVM includes configurable AVDD and DVDD supplies, screw terminals for analog input and digital output access, and on-board linear regulators and transformer drivers for isolated power generation. The AMC1303, AMC1306, and AMC1336 Evaluation Module User's Guide describes the board's operation, analog and digital interfaces, and recommended test configurations.

The AMC1336DWVR addresses a specific but critical need in modern power electronics: the accurate, isolated measurement of high voltages through resistive dividers. Its unique combination of a ±1-V bipolar input, 1.5-GΩ input impedance, 8000-V_PEAK reinforced isolation, and 115-kV/µs transient immunity makes it a natural fit for motor drive, inverter, and charger designs where voltage feedback integrity directly determines system performance and safety. By producing a simple 1-bit bitstream that can be decimated by the host microcontroller's integrated filters, the device minimizes external component count while delivering 16-bit effective resolution at 82 kSPS. For power electronics engineers seeking to simplify isolated voltage sensing without compromising accuracy or safety certification, the AMC1336DWVR provides a compact, well-documented, and production-ready solution.