Digital Power

In the last decades, digital technologies have penetrated many if not most application domains. Power conversion has been lagging for many practical reasons, cost of a digital core being one of them. However, in recent years the situation has changed. Affordable MCU’s containing advanced digital cores and crucial mixed signal peripherals have become available in the market. It’s time to take advantage.

In general a digital implementation allows more flexibility during the design phase of the application. While writing robust firmware code should not be underestimated, when available, fast experimental cycles and debugging become feasible. Improvements to the solutions can be made even in the field by means of firmware updates.
The number of external discrete components reduces when functionality moves to the MCU which has a positive effect on robustness and cost. In terms of cost, it’s not only the material cost of each individual component, but ordering, stock and mounting cost as well. Also the required PCB area for each component adds to the total bill of material.
Testing shifts from the time consuming functional to the more efficient structural domain. Firmware code testing can be faster with higher coverage. As such, simpler test procedures reduce cost and make the solution more robust.
Programmability is an obvious benefit of a digital implementation. Important settings can be adjusted on-the-fly during development to find optimum solutions or to try alternative algorithms. Besides programming also status information can be queried from the controller to run diagnostics on critical parameters.
Where analog implementations thrive for linear algorithms, digital implementations are far more appropriate when non-linearity is involved. An example could be a parabolic compensation curve instead of a linear gain curve. The situation is even more in favour of digital when discontinuities are to be considered. Switching between voltage and current control can be done instantaneous in digital without disturbance whereas for an analog implementations this becomes difficult to achieve.
In combination with mentioned diagnostics, advanced protection mechanisms can be implemented. "if... then..." and "case... if..." kind of detections are in the nature of a digital implementation. Besides detection also the action to be taken when a protection is triggered can be more advanced. For example, a triggered protection could result in a number of automatic restarts of the converter before shutting down and flagging the error condition to a host.
Digital hardware is less susceptible for EMI. Where information in analog signals depends on very small voltage changes, the information of a digital signal is contained in distinct voltage levels, e.g. 3.3V and 0V.
Finally digital technologies open avenues to new features and functionality not possible with analog hardware. Sophisticated algorithms can improve user experiences and add value to a solution.

Finding the right tradeoff between benefits of analog electronics and digital signal processing is not trivial. ZeoN PowerTec bridges the two domains by offering to customers detailed power electronics knowledge in combination with basic embedded programming experience.