800 W PFC demoboard system solution High power density 800 W 130 kHz platinum server design EVAL_800W_130PFC_C7 Garcia Rafael (IFAT PMM ACDC AE) Zechner Florian (IFAT PMM ACDC AE) Table of contents 1 General description 2 Test results 3 Design concept 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 2 Table of contents 1 General description 2 Test results 3 Design concept 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 3 General Description: › The “EVAL_800W_130PFC_C7“ - evaluation board shows how to design an high power density 800 W 130 kHz platinum server supply with Power Factor Correction (PFC) Boost Converter working in Continuous Conduction Mode (CCM). On this purpose the latest CoolMOS™ technology IPP60R180C7 600 V power MOSFET, IDH06G65C5 650 V thinQ!™ SiC Schottky Diode Generation 5, ICE3PCS01G PFC Controller , low-side Non Isolated Gate Driver 2EDN7524F EiceDRIVER™, XMC 1300 Microcontroller and Quasi Resonant CoolSET™ ICE2QR4780Z have been applied. Summary of features: › Output voltage: 380 VDC › Output current: 2.1 A › Efficiency: >96% @ 20% load, Vin = 230 VDC › Switching Frequency: 130 kHz The following variant is available: › 800 W 130 kHz PFC version with CoolMOS™ C7, IPP60R180C7, EVAL_800W_130PFC_C7 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 4 Infineon high power density 800 W 130 kHz platinum server design PWM Controller CoolSETTM ICE2QR4780Z Silicon Carbide Diode 5th G. thinQ!TM IDH06G65C5 Power MOSFETs CoolMOSTM IPP60R180C7 R Zechner Florian Microcontroller XMC 1300 DIGITAL XMC1302-T038X0200 AB 07.10.2015 PFC CCM Controller ANALOG ICE3PCS01G Copyright © Infineon Technologies AG 2015. All rights reserved. EiceDRIVERTM 2EDN7524F 5 Main power board schematic 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 6 Bias board schematic 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 7 Digital control board schematic 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 8 PFC control schematic 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 9 Temperature monitoring and inrush relay control schematic 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 10 PCB layout Top layer 07.10.2015 Bottom layer Copyright © Infineon Technologies AG 2015. All rights reserved. 11 Table of contents 1 General description 2 Test results 3 Design concept 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 12 Requirements Parameter • Input requirements Input voltage range, Vin_range Nominal input voltage, Vin Value AC line frequency range, fAC 47 – 64 Hz Max peak input current, Iin_max 10 ARMS @ Vin = 90 VAC , Pout_max = 800 W , Max load Turn on input voltage, Vin_on Turn off input voltage, Vin_off 80 VAC – 87 VAC, Ramping up 75 VAC – 85 VAC, Ramping down Power Factor Correction (PFC) Shall be greater than 0.95 from 20% rated load and above Hold up time 10 ms after last AC zero point @ Pout_max = 800 W, Vout_min = 320 VDC 90 VAC – 265 VAC 230 VAC • Output features Nominal output voltage, Vout 380 VDC Maximum output power, Pout 800 W Maximum output current, Iout_max Output voltage ripple 2,1 A Max 20 Vpk-pk @ Vout , Iout Output OV threshold maximum 450 VDC Output OV threshold minimum 07.10.2015 420 VDC Copyright © Infineon Technologies AG 2015. All rights reserved. 13 Efficiency High Line and Low Line efficiency with: 2x IPP60R180C7 @ fs = 130 kHz, Rgate(on) = 39 , Rgate(off) = 14 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 14 Table of contents 1 General description 2 Test results 3 Design concept 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 15 Power Factor Correction (PFC) Power Factor Correction (PFC) shapes the input current of the power supply to be in synchronization with the mains voltage, in order to maximize the real power drawn from the mains. In a perfect PFC circuit, the input current follows the input voltage as a pure resistor, without any input current harmonics. This document is to demonstrate the design and practical results of an 800 W 130 kHz platinum server PFC demo board based on Infineon Technologies devices in terms power semiconductors, non-isolated Gate Drivers, analog and digital controllers for the PFC converter as well as Flyback controller for the auxiliary supply. R zechner florian 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 16 Topology of the boost converter Although active PFC can be achieved by several topologies, the boost converter is the most popular topology used in Server PFC applications, for the following reasons: • The line voltage varies from zero to some peak value typically 375 V; hence a step up converter is needed to output a DC bus voltage of 380 V or more. For that reason the buck converter is eliminated, and the buck-boost converter has high switch voltage stress (Vin+Vo), therefore it is also not the popular one. • The boost converter has the filter inductor on the input side, which provides a smooth continuous input current waveform as opposed to the discontinuous input current of the buck or buck-boost topology. The continuous input current is much easier to filter, which is a major advantage of this design because any additional filtering needed on the converter input will increase the cost and reduces the power factor due to capacitive loading of the line. Structure and key waveforms of a boost converter 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 17 PFC modes of operation The boost converter can operate in three modes: Continuous Conduction Mode (CCM), Discontinuous Conduction Mode (DCM), and Critical Conduction Mode (CrCM). Figure 2 shows modeled waveforms to illustrate the inductor and input currents in the three operating modes, for the same exact voltage and power conditions. By comparing DCM among the others, DCM operation seems simpler than CrCM, since it may operate in constant frequency operation; however DCM has the disadvantage that it has the highest peak current compared to CrCM and also to CCM, without any performance advantage compared to CrCM. For that reason, CrCM is a more common practice design than DCM, therefore, this document will exclude the DCM design. PFC inductor and input line current waveforms in the three different operating modes 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 18 EMI filter The EMI filter implemented is as a two-stage filter, which provides sufficient attenuation for both Differential Mode (DM) and Common Mode (CM) noise. The two high current common mode chokes L_cm are based on high permeability toroid ferrite cores. 1. 2 x 26 Turns/ 2 x 4,76 mH 2. 2 x 28 Turns/ 2 x 5,7 mH The relatively high number of turns causes a considerable amount of stray inductance, which ensures sufficient DM attenuation. 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 19 Rectifier bridge The rectifier bridge is designed for the worst case: maximum output power and minimum input voltage. To calculate the input current, an efficiency of 94% (at Vin = 90 V) is applied. 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 20 PFC choke The PFC choke design is based on a toroid high performance powder core. Toroid chokes allow well balanced and minimized core and winding losses, having a homogeneous heat distribution w/o hot spots and a large surface area. Hence they are predestined for systems which are targeting highest power density with forced air convection. Thereby very small choke sizes are feasible. The core material was chosen to be a 60µ Chang Sung Corporation’s (CSC) HIGH FLUX, which has an excellent DC bias and good core loss behavior. The outer diameter of the magnetic powder toroidal core is 27 mm. The winding was implemented using enameled copper wire AWG 16 (1,25 mm diameter). 07.10.2015 Copyright © Infineon Technologies AG 2015. All rights reserved. 21 Support slides 800 W 130 kHz platinum server design Evaluation board page – – – – – Technical description Datasheets Parameters Related material Videos Product family pages – – – – – – – EVAL_800W_130PFC_C7 Product brief Application notes Selection guides Datasheets and portfolio Videos Simulation models 07.10.2015 – – – – – – Copyright © Infineon Technologies AG 2015. All rights reserved. IPP60R180C7 IDH06G65C5 ICE3PCS01G 2EDN7524F XMC 1300 ICE2QR4780Z 22