MAX11046 - Simultaneous-sampling ADC provides true 16-bit performance for polyphase power-grid designs

The high impedance input eliminates precision external buffers on each channel, while the bipolar input saves a level shifter. Furthermore, simultaneous sampling eases the typical requirement for phase-adjust firmware and thus speeds end designs and time to market. Together these benefits simplify the design challenges for power-grid monitoring and measurement equipment while also providing
Electricity providers are investing heavily in power-delivery infrastructure because of rising power demands and a global focus on energy conservation. As a result, advanced real-time, end-to-end powerline monitoring, measurement, and control systems are now critical elements of the new smart grids for both single-phase and multiphase power applications.

To achieve the Class 0.2 (i.e., 0.2% error) equipment classification over the voltage range up to 6000V (fault condition) of a 220V (nominal) system, a design must have a tolerance of ~0.06% to ensure 0.2% compliance with a design margin. These are challenging parameters which call for an ADC of ~93dB dynamic range, i.e., true 16-bit accuracy.

The MAX11046 is the industry's only 16-bit (no missing code), 8-channel, simultaneous-sampling SAR ADC that exceeds the combined industry standards of the IEC 62053 Class 0.2 and meets the 6kV transient voltage specification of EN 50160.


Traditionally, an ADC that provided a high-impedance input for bipolar signals used to require both external positive and negative supply voltages. There were competitive ADCs that offered bipolar-to-ground inputs off a single voltage supply, but they could not provide a high-impedance input and thus required an external input buffer. The MAX11046, however, provides a high-impedance bipolar input and only requires a single positive voltage to operate. The high-impedance input also avoids the costly precision operational amplifier found in traditional designs.

The MAX11046 waives the need for an external negative voltage supply. It eliminates an active input buffer for each channel, and saves up to $1 (U.S.) per channel. These cost savings are significant in applications that require multichannel simultaneous sampling like power-grid power-factor optimization for greater energy efficiency. At 8mm2 per channel, moreover, the MAX11046 provides the industry's lowest area per channel, bettering the nearest competition by 67% per channel.

To ensure accurate 3-phase plus neutral wye system current and voltage measurements in real time, a single MAX11046 provides the eight simultaneous-sampling channels (four voltage and four current) instead of two competitive parts.

This new Maxim ADC also offers the flexibility to operate the digital I/O from 2.7V to 5.25V. This eliminates the need for a level shifter, lowers the number of bypass capacitors, simplifies the design and, again, reduces cost.