Introduction to Digital Power Conversion
XMC4000/1000 Family
Table of Contents
Application Guide 5 V1.0, 2015-01
5.2 Over Voltage and Over Current Protection (OVP / OCP) .................................................................. 50
6 Modulation ........................................................................................................................................ 51
6.1 Voltage Control (VC) .......................................................................................................................... 52
6.1.1 Timing Scheme ............................................................................................................................ 53
6.2 Current Control ................................................................................................................................... 55
6.2.1 Average Current Control (ACC) ................................................................................................... 55
6.2.2 Average Current Control, Edge-Aligned Scheme ........................................................................ 56
6.2.3 Discontinuous to Continuous Current Recovery by Timer-Load ................................................. 58
6.2.4 ACC Center Aligned Scheme ...................................................................................................... 59
6.3 Peak Current Control (PCC) .............................................................................................................. 60
6.3.1 PCC Timing Scheme.................................................................................................................... 62
6.4 Blanking, Filtering and Clamping ....................................................................................................... 63
6.5 Slope Compensation .......................................................................................................................... 64
6.5.1 A Necessity in Fixed Frequency PCC .......................................................................................... 64
6.5.2 Fast Average Current Mode PCC ................................................................................................ 65
6.5.3 V
IN
independent Average Current mode ...................................................................................... 66
6.5.4 Slope Compensation Conditions – PCC ...................................................................................... 67
6.5.5 Slope Compensation Conditions: PCC ‘Stable Area’ examples .................................................. 70
6.5.6 Without Slope Compensation, Fixed-ON-Time (FOT) ZCD Control ............................................ 71
6.5.7 Without Slope Compensation, Fixed-OFF-Time (FOFFT) PCC .................................................. 71
6.6 CCM, CRM (CrCM) and DCM ............................................................................................................ 72
6.7 CRM: PFC using Fixed-On-Time (FOT)............................................................................................. 74
6.8 CCM / (DCM): PFC using Fixed-Off-Time (FOFFT) .......................................................................... 75
6.9 CCM: PFC example using Average Current Mode Control ............................................................... 76
7 Control Loops ................................................................................................................................... 77
7.1 Using CSG (HRPWM) with an Internal Comparator and Slope Generator........................................ 77
7.2 Using embedded ACMP and external Slope Compensation Ramp .................................................. 78
7.3 Using FADC Compare Mode; Slope Compensation Add-On ............................................................ 81
7.4 Open Loop Gain Stabilization (Frequency Compensation)................................................................ 83
7.4.1 Open Loop Gain Voltage Mode ................................................................................................... 84
7.4.2 Open Loop Gain Bode Plot, Voltage Mode Stabilization ............................................................. 85
7.4.3 Open Loop Gain Current Mode w/ Slope Compensation ............................................................ 86
7.4.4 Open Loop Gain Bode Plot, Current Mode Stabilization ............................................................. 87
8 Application Software ....................................................................................................................... 88
8.1 Advanced Algorithms / User software IP for Power Conversion ........................................................ 88
8.2 Multi-stage, multi-functional, multi-tasking control by a single controller ........................................... 88
8.3 Safety ................................................................................................................................................. 89
8.4 Communication capabilities ............................................................................................................... 89
8.5 Data logging / Firmware updates ....................................................................................................... 89
8.6 Human Machine Interface .................................................................................................................. 89
8.7 Digital Switch Mode Control by New Feed-Forward Techniques ...................................................... 90
8.8 Non-linear Slope Compensation ........................................................................................................ 90