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Maxim introduced the 8-channel, 16-bit, simultaneous-sampling ADC MAX11046. The device uses a unique architecture (patent pending) to generate an on-chip negative rail with very low noise. This architecture enables true 16-bit performance under a single external positive supply and high-impedance bipolar inputs, exceeding the IEC 62053 requirement for class 0.2 accuracy (0.2% at 220 V). High-impedance inputs eliminate the need for an external high-precision buffer on each channel, and bipolar inputs avoid the need for level shifters. Simultaneous sampling also simplifies phase-adjustment firmware, shortening development time. These advantages simplify grid monitoring and measurement equipment design while reducing cost, board area, and power consumption.
Evolving smart grid design requirements
Growing electricity demand and global attention to energy efficiency have driven increased investment in power transmission infrastructure. As a result, advanced real-time, end-to-end power-line monitoring, measurement, and control systems have become essential components of single-phase and multi-phase smart grid applications.
To achieve device-level class 0.2 accuracy (0.2% error) for a nominal 220 V system across the full voltage range—where fault conditions can raise voltages to as high as 6000 V—the system design must provide about 0.06% margin to meet the 0.2% accuracy requirement with design margin. This places demanding requirements on ADC performance: roughly 93 dB of dynamic range is needed to deliver true 16-bit accuracy.
The MAX11046 is one of the industry’s few 16-bit (no missing codes), 8-channel, simultaneous-sampling SAR ADCs capable of exceeding the IEC 62053 class 0.2 accuracy requirement while meeting the EN 50160 standard for 6 kV transient voltages.
Unique performance benefits reduce cost and space
ADC designs that provide high-impedance inputs for bipolar signals typically require both positive and negative external supplies. Some competing ADCs offer ground-referenced bipolar inputs on a single supply but cannot support high-impedance inputs, necessitating an external input buffer. The MAX11046 supports high-impedance bipolar inputs while requiring only a single positive supply. High-impedance inputs also remove the need for costly precision operational amplifiers commonly used in traditional designs.
The MAX11046 does not require an external negative supply. Each channel also does not require an active input buffer, saving approximately $1 USD per channel. This cost saving is important for applications that require multiple channels to sample simultaneously, for example to optimize grid power factor and improve energy efficiency. The MAX11046 occupies only 8 mm2 per channel, among the smallest in the industry, saving about 67% of board area per channel compared with similar competing products.
The MAX11046 provides eight simultaneous-sampling channels (four voltage channels and four current channels). A single MAX11046 can accurately measure current and voltage on a three-phase Y system with a neutral in real time, whereas competing solutions typically require two devices.
This Maxim ADC also supports a digital I/O supply range from 2.7 V to 5.25 V, increasing system flexibility, eliminating level shifters, reducing the number of bypass capacitors, simplifying designs, and further lowering cost.
