Datasheet

6 Intelligent Power Supply Design Solutions
Full digital control replaces the standard analog control loop
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 allows
the designer to employ techniques that are not possible with
the analog solution, including proprietary digital compensation
algorithms and non-linear control techniques. 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.
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Single Ended
Power Factor Correction
dsPIC
®
DSC
MCP1416
FET Driver
ADC
Channel
ADC
Channel
ADC
Channel
PWM
Output
V
AC
VAC
VHV_BUS
IPFC
Input Voltage
Feedback
Current
Feedback
Output Voltage
Feedback
Power Factor Correction (PFC) is essential
in higher wattage power supplies to reduce
harmonic content, system losses and
radiated emissions. In this example the
dsPIC DSC simplifies the implementation
of a Boost-PFC algorithm using Average
Current Mode Control. The PWM command
is calculated digitally by computing the
product of rectified input voltage, the
output of the voltage error compensator
and the output of the voltage Feed-Forward
Compensator. The digital PFC function
uses few DSC resources, leaving plenty of
additional capability to perform the rest of
the primary side control.
PFC with Advanced Digital Control
Microchip’s 16-bit dsPIC® DSCs enable
the Level 4 solution. Feedback from the
power supply is obtained using high-speed
ADCs. The power supply is controlled using
specialized high-speed 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.
Moving to a Higher Level: Level 4 Full Digital Control
Power Supply Design Integration Levels