Level 4 Full Digital Control
Contents
Level 4 Full Digital Control replaces the standard analog design and also provides the power management functions of Levels 1-3 integration. The power supply regulation function is directly controlled by the digital circuits on the processor and the software running on the processor. The full digital solution enables a customized response to power input change or load change events, which can lower system cost and increase system efficiency. The full digital solution allows the designer to employ techniques that are not possible with the analog solution, including proprietary digital compensation algorithms and non-linear control techniques.
Microchip's 16-bit dsPIC® DSCs have the ability to implement Full Digital Control techniques. The high-performance CPU and rich peripherals of the dsPIC Digital Signal Controller (DSC) devices enable solutions that do not require much in the way of external support chips. In addition to the space and cost-saving features that are in the dsPIC DSC solutions, they also have special features enabling advanced power conversion. Feedback from the power supply is obtained using high-speed ADCs. The power supply is controlled using specialized high-speed Pulse Width Modulation (PWM) peripherals. The PWM module can directly drive all popular power supply topologies and the CPU core allows digital compensation algorithms to be executed quickly. dsPIC DSCs can be used for various power conversion and power control applications, and they offer higher power density, lower system cost, improved reliability, and lower manufacturing and maintenance costs.
Level 4 Integration Examples
PFC with Advanced Digital Control
Power Factor Correction (PFC) is essential in higher-wattage power supplies to reduce harmonic contents, system losses, and radiated emissions. In this example, the dsPIC DSC simplifies implementing Boost-PFC algorithms with the Average Current Mode Control technique. The current signal is calculated digitally by computing the product of the rectified input voltage, the output of voltage error compensator and output of voltage feed-forward compensator. Implementing the digital PFC function uses little of the DSC resources, leaving plenty of additional capability to perform the rest of the primary side control.
AC-DC Conversion with Complete Digital Control
Are you facing challenges in designing an efficient, reliable, cost-effective AC-DC power supply with advanced features? Our family of dsPIC DSCs can help optimize design cycles effectively. The high-speed PWM module with multiple advanced operating modes helps implement various advanced conversion stages such as PFC, phase shift, zero voltage, transition converter with full-bridge conversion and synchronous rectification, and multi-phase buck converters. Our high-speed ADC can be triggered on an edge of the PWM to sample the various voltages and currents for high-speed processing. The high-performance CPU helps implement advanced PID digital control loops and compensators in software.
Full Digital DC-DC Conversion
The dsPIC33FJXXGS dsPIC DSC is power efficient and highly integrated DC-DC converters dynamically control different power stages. In this example, dsPIC33FJ16GS502, high-speed Analog-to-Digital Converter (ADC), PWM, and comparators work together without using much CPU bandwidth. Faster digital control loops and compensators can be executed using a high-performance Digital Signal Processor (DSP) engine. Advanced features such as dynamic load response, protections, sequencing, remote control, and communications can also be implemented.
Reference
