Digital Control

The advances of modern technology are bringing down the cost of high performance micro controllers. These combined with a rich set of suitable peripherals enable digital control of SMPS at feasible mass volume prices. The designers no longer need to work with complex and over-sized DSPs, while adapting to the intricate implementations of different vendors, to implement flexible modulation schemes and process the calculations in a time-efficient manner. The low end of ARM® Cortex™-M family thus are very suitable candidates for this task as they are widely deployed and proven, meaning the support and development structure is in place and engineers are comfortable working with them. Control algorithms such as traditional PID and other techniques may be programmed in to achieve improved system dynamics and deployment flexibility. Combined with well balanced peripheral sets and with the addition of analogue circuitry for sampling data these rise to the task of controlling a new generation of SMPS with unrivaled efficiency figures and increased power density.

The ICERGi digital controllers are implemented as compact PCBs for ready placement on main boards of systems. They are based on the cost-effective ARM® Cortex™-M0 processors because of their proven reliability, extensive deployment and rich peripheral sets. ICERGi controllers enable multilevel  from 200W to 3kW and are readily applied to different typologies and variants.

PFC Control

ICERGi PFC/Inverter Controllers have hardware that is compatible with operation of a module either as a PFC stage or as an Inverter with appropriate software provision, also allowing operation either in 3-level or 5-level modes. Proprietary algorithms are used, optimising transient response and current THD with low values of bulk capacitance. The operational block diagram is as below.

Fig. 1 Digital PFC Control – Block diagram

 

LLC Control

ICERGi can operate with stacked low-voltage FETs to achieve GaN-type (or better) performance at ~400KHz operating frequency.
ICERGi LLC control in ExtraBoost™ mode operates with two different gain bands, with the higher-gain operation being selected when the input voltage drops.  This allows deeper discharge of the bulk capacitor – down to almost 200V – thus providing longer holdup time for a given value of electrolytic capacitance, or alternatively usage of a smaller capacitance value for given holdup time.  Where such performance is not a requirement, the flexible architecture allows for operation of a half-bridge in a mode with a balanced inductor, facilitating low common-mode noise.