STEVAL-ISF002V1 STMicroelectronics, STEVAL-ISF002V1 Datasheet - Page 9

• Manufacturer Part Number: STEVAL-ISF002V1
• Description: BOARD EVALUATION
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISF002V1

• Main Purpose: *
• Embedded: *
• Utilized Ic / Part: *
• Primary Attributes: *
• Secondary Attributes: *
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-10422

UM0877
2.2
Figure 3.
Figure 2.
PFC with digital approach
●
From a theoretical point of view, it could be possible to replace an existing analog solution
made up of discrete components with ST’s digital solution, in which case, other than the
PFC control, the same MCU would also manage the main application.
To perform a digital power factor corrector, a microcontroller needs to have information
about three main system parameters. These are the output DC voltage, the input AC voltage
and the inductor current.
These parameters, appropriately scaled down, are managed by the microcontroller that
modulates the switching of the MOSFET to have the input current in phase with the input AC
voltage while keeping the output DC voltage to a fixed and stable value.
A generic implementation scheme for a digital PFC is shown in
AC to DC boost converter signals
with CCM PFC - output VDC, input
Vac and inductor current
(time scale = 5 ms)
A digital implementation for a PFC gives some advantages.
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–
–
Easy implementation of sophisticated control algorithms.
Quick software modifications to meet specific requirements.
Simple integration with other applications.
Scheme of AC to DC boost converter topology
Doc ID 16854 Rev 1
Figure 4.
PFC basics and operating principles
AC to DC boost converter signals
with CCM PFC - inductor current
and power MOSFET gate command
(time scale = 10 µs)
Figure
5.
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