Digital Power

What is Digital Power?

Digital power is an energy conversion system in which digital control techniques are applied to power management applications where monitoring, communication and supervisor functions come as an extension of the main digital control loop or in conjunction of the main analog control loop.

From low- to high-power applications, digital power management and control, mainly applied to Switched-Mode Power Supplies (SMPS), increases power density, enables faster control loops, better system-level integration and design flexibility, improves system-level reliability, monitoring and safety, and helps reduce time-to-market. Overall, digital power control enhances system efficiency.

ST's offering

ST's extensive digital power portfolio meets the requirements of digital power designs. Our offering includes MCUs specifically designed to address digital power conversion applications with a full digital control approach, as well as ASICs and ASSPs addressing semi-digital (mixed analog-digital signal) control and digital controllers with a dedicated ROM memory for software control algorithms.

ST's power discretes optimized for soft switching resonant and hard switching converters maximize system efficiency for low-power and high-power applications.

ST's digital power solutions can be implemented using dedicated evaluation boards, reference designs,  technical documentations, and eDesignSuite software configurator and design tools.

Digital Power vs Analog Power

• Key benefits

  • Digital power

    • Immune to environmental conditions (temperature, drift, etc)
    • SW programmable and flexible solution (i.e. one design for different solutions)
    • Advanced control possible (non-linear, multi variable)
    • Failure prediction (integration of communication / monitoring functions and control algorithm in the same IC)

    Analog power

    • High bandwidth and resolution
    • Cost-efficient solution
    • Well-known theory

• Drawbacks

  • Digital power

    • Bandwidth limitations (sampling loop)
    • PWM frequency and resolution limits (not for HRTIMER)
    • Quantization issues
    • Bias power supplies, interface requirements

    Analog power

    • Component drift / aging / tolerance
    • Hardware-based: lack of flexibility
    • Limited to classical control theory only
    • No smart control over performance
    • Limited number of power stages / topologies

• Required components

  • Digital power

    • External gate driver required
    • Auxiliary supply with different voltages:
      • 3.3 and 5 V for MCUs (impacting on level translation of external sensing)
      • 5 to 20 V for gate drivers (also negative)

    Analog power

    • Gate driver usually implemented in IC
    • Power can directly be supplied from HV startup, rather than from auxiliary winding after startup