Maxim Integrated Simplifies System Monitoring With Five ICs in One
As power differences grow between industrial equipment and digital electronics, interfacing can be a challenge. Maxim Integrated has a possible solution to help.
As industrial equipment gets higher and higher power, digital electronics get lower and lower power. A key concern is how to interface the two safely?
Moving to greater autonomy in electronics often entails creating systems with a stronger ability to self-monitor and self-regulate. This pursuit is undoubtedly growing throughout the industry; however, some fields, specifically high-power fields like industrial, are facing challenges.
One significant challenge is that the field-side circuitry (the system to be monitored) is generally extremely high voltage/power analog signals. Yet, the logic-side circuitry (the monitoring circuitry itself) is usually very low-power digital.
An example of an AC/current line monitoring system. Image used courtesy of Maxim Integrated
For safety concerns, one cannot simply apply these high power voltage and current signals directly––levels of galvanic isolation are needed, but this requires extra circuitry and cost.
Recently, Maxim Integrated made news with its release of its MAX22530, a device which, it hopes, could alleviate this challenge.
A Standard, High Voltage Monitoring System
A standard industrial monitoring system typically requires many components to safely and reliably interface between the power signals and the digital monitoring circuitry.
The standard signal flow begins on the field-side, where the power signal, generally a voltage signal, gets applied to an analog-to-digital converter (ADC). This ADC samples and converts the power signal to a digital signal which then gets transmitted via SPI. To interconnect the SPI interface with the MCU, digital isolation, typically optocouplers, are used.
Simplified block diagram of a high voltage monitoring system. Image used courtesy of Maxim Integrated
In terms of simplicity, area, and cost, this method is far from ideal. Not only are all of these components necessary, but the isolator circuitry itself requires its separate power supply and routing. When trying to make systems small and straightforward, this approach is far from perfect.
"All-in-one" Monitoring Circuits: the MAX22350
Maxim Integrated released its MAX22350, a new integrated solution that combines all necessary monitoring circuitry onto one IC.
The MAX22530 is a single package that consists of a 4-channel, galvanically isolated 12-bit ADC with a reference voltage, logic control, SPI interface, and an integrated DC-DC converter to power all field-side circuitry.
This use of components means that not only does this offering eliminate the need for all of the aforementioned discrete components, but it also removes the need for an external power supply for field-side electronics, hugely saving space and cost. Specifically, the integration allows for a 250mm2 solution size, which Maxim says is 40% smaller than the 420mm2 size for the closest discrete solution.
Block diagram of the MAX22350. Image used courtesy of Maxim Integrated
Arguably more impressive than the space savings is the performance that this device claims to offer. According to Maxim, the MAX22530 delivers a 50x improvement in measurement accuracy compared to a discrete solution, taking it from +/- 50% to +/- 1%, respectively. The company claims these improvements result from the integration, which allows for better system performance with less external influences.
Progressing Towards Autonomy
As more and more devices seek autonomy, they will undoubtedly need the ability to self-monitor and self-regulate. Maxim Integrated’s newest solution hopes to be able to address this challenge in industrial design by not only decreasing board space but also significantly improving performance.