VIA PFM™ Family PFA175x240x400Axx ® S US C C NRTL US Isolated AC-DC Converter with PFC in 125 mm Package Features & Benefits Product Description • Universal input (85 to 264 VAC) The VIA PFM is a highly advanced 400 W AC-DC converter operating from a rectified universal AC input which delivers an isolated and regulated Safety Extra Low Voltage (SELV) 24 V secondary output. • 24 VOUT, regulated, isolated • 400 W maximum power • High efficiency This unique, ultra-low profile module incorporates AC-DC conversion, integrated filtering and transient surge protection in a chassis mount or PCB mount form factor. • Built-in EMI filtering • Chassis mount or board mount packaging options • Always-on, self-protecting converter control architecture • SELV Output • Two temperature grades including operation to -40°C • Robust package • Versatile thermal management • Safe and reliable secondary-side energy storage The VIA PFM enables a versatile two-sided thermal strategy which greatly simplifies thermal design challenges. When combined with downstream Vicor DC-DC conversion components and regulators, the VIA PFM allows the Power Design Engineer to employ a simple, low-profile design which will differentiate the end-system without compromising on cost or performance metrics. • High MTBF • 127 W/cubic inch power density • External rectification and transient protection required Typical Applications • Small cell base stations • Telecom switching equipment • LED lighting • Test and measurement equipment • 200 - 400 W Industrial power systems • Office equipment Size: 4.91 x 1.40 x .37 in 124.8 x 35.5 x 9.3 mm Part Ordering Information Device Input Voltage Range Package/Pin Type Output Voltage x 10 Temperature Grade Output Power Revision Package Size Version VIA PFM 175 x x x 400 A x x PFA = VIA PFM 175 = 85 to 264 V B = Chassis C = PCB Short Pin G = PCB Long Pin 240 = 24.0 V T = Telecom C = Comm 400 = 400 W A 3 = 125 mm 3 = Always On VIA PFM™ Family Rev 1.0 vicorpower.com Page 1 of 22 04/2015 800 927.9474 PFA175x240x400Axx Typical PCB Mount Applications J1 24 V Filter ~ 85 264 Vac C4 + VIA PFM™ MOV ~ + _ 24 V 10 A +OUT +IN D1 – -IN + + + C1 C2 C3 -OUT 2 x Cool-Power® ZVS Buck Cool-Power® ZVS Buck + _ 3.3 V 10 A + _ 1.8 V 8 A The PCB terminal option allows mounting on an industry standard printed circuit board, with two different pin lengths. Vicor offers a variety of downstream DC-DC converters driven by the 24V output of the VIA PFM. The 24V output is usable directly by loads that are tolerant of the PFC line ripple, such as fans, motors, relays, and some types of lighting. Use downstream DC-DC Point of Load converters where more precise regulation is required. Parts List for Typical PCB Mount Applications J1 Delta 06AR2 EMI Filter Entry Module, C14 6 A 250 V 5 x 20 mm fuseholder F1 (mount in J1) Littelfuse 0216008.MXP 8 A 250 VAC 5 x 20 mm holder D1 Fairchild GBPC1210W 12 A 100 V PTH Nichicon UVR1V153MRD 15,000 µF 35 V 4.3 A 25 x 50 mm bent 90° or C1, C2, C3 CDE 380LX153M035A022 15,000 µF 35 V 5.6 A 35 x 30 mm snap in or Sic Safco Cubisic LP A712062 22,000 µF 35 V 5.8 A 45 x 75 x 12 mm rectangular C4 Panasonic ECQ-U2A474ML 0.47 µF 275 V VIA PFM™ Family Rev 1.0 vicorpower.com Page 2 of 22 04/2015 800 927.9474 PFA175x240x400Axx Typical Chassis Mount Applications J1 24 V Filter ~ 85 264 Vac C4 +OUT +IN D1 + Fan VIA PFM™ MOV ~ – C1 C2 C3 -OUT -IN 8 Relays 8 16 Dispensors Controller Coin Box The VIA PFM is available in Chassis Mount option, saving the cost of a PCB and allowing access to both sides of the power supply for cooling. The parts list below minimizes the number of interconnects required between necessary components, and selects components with terminals traditionally used for point to point chassis wiring. Parts List for Typical Chassis Mount Applications J1 Delta 06AR2 EMI Filter Entry Module, C14 6 A 250 V 5 x 20 mm fuseholder F1 (mount in J1) Littelfuse 0216008.MXP 8 A 250 VAC 5 x 20 mm holder D1 Fairchild GBPC1210FS 12 A 1000 V 0.25” QC TERMINAL C1, C2, C3 Nichicon LNT1V153MSE 35 V 5.1 A 35 x 83 mm screw terminal or C1 Kemet ALS30A23KE063 35 V 14.2 A 51 x 84 mm screw terminal C4 Panasonic ECQ-U2A474ML 0.47 µF 275 V MOV Littelfuse TMOV20RP300E VARISTOR 10 kA 300 V 250J 20 mm VIA PFM™ Family Rev 1.0 vicorpower.com Page 3 of 22 04/2015 800 927.9474 PFA175x240x400Axx Absolute Maximum Ratings The absolute maximum ratings below are stress ratings only. Operation at or beyond these maximum ratings can cause permanent damage to the device. Parameter Comments Min Max Unit Input voltage +IN to –IN 1 ms max 0 600 Vpk Input voltage (+IN to -IN) Continuous, Rectified 0 275 VRMS -0.5 29 VDC Output voltage (+Out to -Out) 0.0 24.7 A Operating junction temperature T-Grade -40 125 °C Storage temperature T-Grade -40 125 °C Dielectric Withstand* See note below Input-Case Basic Insulation 2121 Vdc Input-Output Reinforced Insulation 2121 Vdc Output-Case Functional Insulation 707 Vdc Output current 20.00 500 16.00 400 12.00 300 8.00 200 4.00 100 0.00 0 -60 -40 -20 0 20 40 60 Case Temperature (°C) Current Power Safe Operating Area VIA PFM™ Family Rev 1.0 vicorpower.com Page 4 of 22 04/2015 800 927.9474 80 100 Output Power (W) Output Current (A) * Please see Dielectric Withstand section. See page 18. PFA175x240x400Axx Electrical Specifications Specifications apply over all line and load conditions, 50 Hz and 60 Hz line frequencies, TJ = 25°C, unless otherwise noted. Boldface specifications apply over the temperature range of the specified product grade. COUT is 44,000 µF +/- 20% unless otherwise specified. Attribute Symbol Conditions / Notes Min Typ Max Unit 264 VRMS 600 V 148 VRMS Power Input Specification Input voltage range, continuous operation VIN Input voltage range, transient, non-operational (peak) VIN Input voltage cell reconfiguration low-to-high threshold VIN-CR+ Input voltage cell reconfiguration high-to-low threshold VIN-CR- 85 1 ms 145 132 Input current (peak) IINRP Source line frequency range fline Power factor PF Input power >200 W Input inductance, maximum LIN Differential mode inductance, common mode inductance may be higher Input capacitance, maximum CIN After bridge rectifier, between +IN and - IN 135 See Figure 8, Startup Waveforms 47 VRMS 12 A 63 Hz 0.96 1 mH 1.5 µF 7 W No Load Specification Input power – no load, maximum PNL Power Output Specification Output voltage set point VOUT VIN = 230 Vrms, 100% Load 23 25 V Output voltage, no load POUT-NL Over all operating steady state line conditions 21 26 V Output voltage range (transient) VOUT Non-faulting abnormal line and load transient conditions 15 28.8 V Output power POUT See SOA on Page 4 400 W VIN = 230 V, full load, exclusive of input rectifier losses Efficiency h 90.5 24 92 % 85 V < VIN < 264 V, full load, exclusive of input rectifier losses 90 % 85 V < VIN < 264 V, 75% load, exclusive of input rectifier losses 90 % Output voltage ripple, switching frequency VOUT-PP-HF Over all operating steady-state line and load conditions, 20 MHz BW, measured at C3, Figure 5 100 1000 mV Output voltage ripple line frequency VOUT-PP-LF Over all operating steady-state line and load conditions, 20 MHz BW 1.5 3.5 V Output capacitance (external) COUT-EXT Allows for ±20% capacitor tolerance 60000 µF Output turn-on delay TON From VIN applied 500 1000 ms Start-up setpoint aquisition time TSS Full load 500 1000 ms Cell reconfiguration response time TCR Full load 5.5 11 ms 20 % 600 ms Voltage deviation (transient) %VOUT-TRANS 27000 -37.5 Recovery time TTRANS Line regulation %VOUT-LINE Full load 3 % Load regulation %VOUT-LOAD 10% to 100% load 3 % SOA 16.7 A 20 ms duration, average power ≤POUT, max 24.7 A Output current (continuous) Output current (transient) IOUT IOUT-PK 300 VIA PFM™ Family Rev 1.0 vicorpower.com Page 5 of 22 04/2015 800 927.9474 PFA175x240x400Axx Electrical Specifications (Cont.) Specifications apply over all line and load conditions, 50 Hz and 60 Hz line frequencies, TJ = 25°C, unless otherwise noted. Boldface specifications apply over the temperature range of the specified product grade. COUT is 44,000 µF +/- 20% unless otherwise specified. Attribute Symbol Conditions / Notes Min Typ Max Unit 74 83 VRMS Powertrain Protections Input undervoltage turn-on VIN-ULVO+ Input undervoltage turn-off VIN-ULVO- Input overvoltage turn-on VIN-ULVO- Input overvoltage turn-off VIN-ULVO+ Output overvoltage threshold VOUT-ULVO+ Upper start / restart temperature threshold (case) TCASE-OTP- See Timing Diagram See Timing Diagram Instantaneous, latched shutdown 65 71 VRMS 265 270 VRMS 29 273 287 VRMS 30.5 32 V 100 °C Overtemperature shutdown threshold (junction) TJ-OTP+ 125 °C Overtemperature shutdown threshold (case) TCASE-OTP+ 110 °C Overcurrent blanking time TOC Based on line frequency Input overvoltage response time TPOVP Input undervoltage response time TUVLO Output overvoltage response time TSOVP 400 460 550 ms 40 ms Based on line frequency 200 ms Powertrain on 30 ms Short circuit response time TSC Powertrain on, operational state 270 µs Fault retry delay time TOFF See Timing Diagram 10 s Output power limit PPROT 50% overload for 20 ms typ allowed VIA PFM™ Family Rev 1.0 vicorpower.com Page 6 of 22 04/2015 800 927.9474 400 W Output Input VIA PFM™ Family Rev 1.0 vicorpower.com Page 7 of 22 04/2015 800 927.9474 ILOAD VOUT EN VIN-RMS tON ≈30VRMS VIN-UVLO+ 1 Input Power On & UV Turn-on VOUT-NL VOUT 2 3 Full 10% Load Load Applied Applied tEN-DIS 4 EN Forced Low tON 5 EN High tSS VIN-CR+ tPOVP tON tSS VIN-OVLO- 7 8 Input Input OV OV Turn-off Turn-on VIN-OVLO+ tCR 6 Range Change LO to HI tCR VIN-CR- 9 Range Change HI to LO tUVLO VIN-UVLO- 11 12 Load Input Power Step Off & UV Turn-off tTRANS (2 places) 10 Load Dump PFA175x240x400Axx Timing diagram Output Input VIA PFM™ Family Rev 1.0 vicorpower.com Page 8 of 22 04/2015 800 927.9474 ILOAD VOUT EN VIN-RMS tSS tON VIN-UVLO+ 13 Input Power ON & UV Turn-on tOFF+tON tOC tOC 14 Output OC Fault tOFF+tON tOC 15 Output OC Recovery )) tSOVP )) )) * )) )) )) )) )) )) VOUT-OVLO+ * 18 Output OVP Fault )) tON 17 Toggle EN (Output OVP Recovery) )) )) 16 Output OVP Fault VIN-UVLO+ tON 19 Recycle Input Power (Output OVP Recovery) tSC tOFF+tON 20 Output SC Fault tOFF+tON 21 Output SC Recovery ≥tOFF+tON VIN-UVLO- 22 23 24 OT Fault Line Input & Drop-Out Power Recovery Off & UV Turn-off PFA175x240x400Axx Timing diagram (Cont.) PFA175x240x400Axx No Load Power Dissipation Application Characteristics Full Load Efficiency 92.00 91.80 91.60 91.40 91.20 91.00 90.80 90.60 3.00 2.50 2.00 1.50 1.00 0.50 0.00 90.40 85 105 125 145 165 185 205 225 245 85 265 105 125 145 -40°C 205 225 245 265 20°C 80°C Figure 2 — Typical no load power dissipation vs. VIN , module enabled 1.00 800 0.98 700 0.96 Power Factor Current (mA) 185 Input Line Voltage Line Voltage Figure 1 — Full load efficiency vs. line voltage 165 600 500 400 300 0.94 0.92 0.90 0.88 0.86 200 0.84 100 0.82 0.80 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 0 100 200 300 400 Output Power (W) 230 V, 50 Hz 1/3x EN61000-3-2, Class A EN61000-3-2, Class D VIN: 120 V/60 Hz 230 V/50 Hz 100 V/50 Hz Figure 3 — Typical input current harmonics, full load vs. VIN using typical applications circuit on pages 2 & 3 Figure 4 — Typical power factor vs. VIN and IOUT using typical applications circuit on pages 2 & 3 Figure 5 — Typical switching frequency output voltage ripple waveform, TCASE = 30ºC, VIN = 230 V, IOUT = 16.7 A, no external ceramic capacitance, 20 MHZ BW Figure 6 — Typical line frequency output voltage ripple waveform, TCASE = 30ºC, VIN = 230 V, IOUT = 16.7 A, COUT = 44,000 µF. 20 MHZ BW VIA PFM™ Family Rev 1.0 vicorpower.com Page 9 of 22 04/2015 800 927.9474 PFA175x240x400Axx Application Characteristics (Cont.) Figure 7 — Typical output voltage transient response, TCASE = 30ºC, VIN = 230 V, IOUT = 16.7 A, 4.2 A COUT = 44,000 µF Figure 8 — Typical startup waveform, application of VIN , RLOAD = 1.4 Ω, COUT = 44,000 µF Figure 9 — 230 V, 120 V range change transient response 16.7 A, IOUT = 16.7 A, COUT = 44,000 µF Figure 10 — Line drop out, 230 V 50 Hz, 0° phase, IOUT = 16.7 A, COUT = 44,000 µF Figure 11 — Line drop out, 230 V50 Hz, 90° phase, VIN = 230 V, IOUT = 16.7 A, COUT = 44,000 µF Figure 12 — Typical line current waveform, 60 Hz, VIN = 120 V, 60 HZ IOUT = 16.7 A, COUT = 44,000 µF VIA PFM™ Family Rev 1.0 vicorpower.com Page 10 of 22 04/2015 800 927.9474 PFA175x240x400Axx Application Characteristics (Cont.) Marker 2 [T1] Det 61.80 dB V Att 20 dB 999.00000000 kHz INPUT 2 100 MA Trd Att 20 dB 9 kHz Meas T 20 ms Unit dB V 10 MHz 2 [T1] 61.80 dB V 1 MHz Det 55022RED ResBW INPUT 2 100 MA Trd ResBW 9 kHz Meas T 20 ms Unit 1 MHz 55022RED dB V 10 MHz 999.00000000 kHz 1 [T1] 90 80 76.61 dB V 198.00000000 kHz SGL 22QPA 1 90 SGL 80 1MA 22QPA 1MA 70 70 2 22QPB 22QPB 60 60 50 50 40 40 30 30 17.Mar 2015 08:49 20 Date: 150 kHz 30 MHz 17.MAR.2015 Date: 08:49:31 Figure 13 — Typical EMI Spectrum, Peak Scan, 90% load, 115 VIN, COUT = 44,000 µF, No Inlet Filter, C4 Marker 2 [T1] Det 61.57 dB V Att 20 dB 978.00000000 kHz INPUT 2 100 20.Mar 2015 14:59 20 150 kHz MA Trd 9 kHz Meas T 20 ms Unit dB V 10 MHz 2 [T1] 61.57 dB V 14:59:08 Figure 14 — Typical EMI Spectrum, Peak Scan, 90% load, 115 VIN, COUT = 44,000 µF using Typical Chassis Mount Application Circuit 55022RED ResBW 1 MHz 30 MHz 20.MAR.2015 Det Marker 1 [T1] 57.24 dB V Att 20 dB 158.00000000 kHz INPUT 2 100 MA Trd 9 kHz Meas T 20 ms Unit dB V 10 MHz 1 [T1] 57.24 dB V 1 MHz 978.00000000 kHz 1 [T1] 90 80 158.00000000 kHz 73.94 dB V 230.00000000 kHz SGL 22QPA 1 55022RED ResBW 2 [T1] 90 80 1MA 70 54.30 dB V 19.90300000 MHz SGL 22QPA 1MA 70 2 22QPB 22QPB 60 60 1 50 50 40 40 30 30 2 17.Mar 2015 09:21 30 MHz 17.MAR.2015 150 kHz 09:21:58 Date: Figure 15 — Typical EMI Spectrum, Peak Scan, 90% load, 230 VIN, COUT = 44,000 µF, No Inlet Filter, C4 92 88 30 86 25 84 20 15 82 10 80 5 0 78 4 6 8 10 12 14 16 18 45 40 90 Efficiency (%) Efficiency (%) 35 15:36:59 92 Power Dissipation (W) 40 30 MHz 20.MAR.2015 Figure 16 — Typical EMI Spectrum, Peak Scan, 90% load, 230 VIN, COUT = 44,000 µF using Typical Chassis Mount Application Circuit 45 90 2 20.Mar 2015 15:36 20 150 kHz 35 88 30 86 25 84 20 15 82 10 80 5 0 78 2 4 6 10 12 14 16 18 Load Current (%) Load Current (%) VIN: 8 85 V 115 V 230 V Eff 85 V 115 V 230 V P Diss Figure 17 — VIN to VOUT efficiency and power dissipation vs. VIN and IOUT , TCASE = -40ºC VIN: 85 V 115 V 230 V Eff 85 V 115 V 230 V P Diss Figure 18 — VIN to VOUT efficiency and power dissipation vs. VIN and IOUT , TCASE = 20ºC VIA PFM™ Family Rev 1.0 vicorpower.com Page 11 of 22 04/2015 800 927.9474 Power Dissipation (W) 20 Date: PFA175x240x400Axx Application Characteristics (Cont.) 45 40 Efficiency (%) 90 35 88 30 86 25 84 20 15 82 10 80 Power Dissipation (W) 92 5 0 78 2 4 6 8 10 12 14 16 18 Load Current (%) VIN: 85 V 115 V 230 V Eff 85 V 115 V 230 V P Diss Figure 19 — VIN to VOUT efficiency and power dissipation vs. VIN and IOUT , TCASE = 80ºC VIA PFM™ Family Rev 1.0 vicorpower.com Page 12 of 22 04/2015 800 927.9474 PFA175x240x400Axx General Characteristics Specifications apply over all line and load conditions, 50 Hz and 60 Hz line frequencies, TC = 25°C, unless otherwise noted. Boldface specifications apply over the temperature range of the specified Product Grade. Attribute Symbol Conditions / Notes Min Typ Max Unit Mechanical Length L 124.8 / [4.91] mm / [in] Width W 35.5 / [1.40] mm / [in] Height H 9.3 / [0.37] mm / [in] Volume Vol 42.0 / [2.56] cm3/ [in3] Weight W 156 / [5.5] g / [oz] Without heatsink Pin material C10200 copper, full hard Underplate Nickel 100 150 Pin finish Pure matte tin, whisker resistant chemistry 200 300 C - Grade, see derating curve in SOA -20 100 °C T - Grade, see derating curve in SOA -40 100 °C µin Thermal Operating case temperature TC Thermal resistance, junction to case, top RJC_TOP 1.04 °C/W Thermal resistance, junction to case, bottom RJC_BOT 1.83 °C/W RHOU 0.15 °C/W 32 J/K Coupling thermal resistance, top to bottom of case, internal Shell Thermal capacity Thermal design See Thermal Design on Page 17 Assembly ESD rating ESDHBM Human Body Model, “JEDEC JESD 22-A114C.01” ESDMM Machine Model, “JEDEC JESD 22-A115B” N/A ESDCDM Charged Device Model, “JEDEC JESD 22-C101D” 200 1,000 V Safety cTÜVus (EN60950-1) Agency approvals/standards cURus (UL/CSA 60950-1) CE, Low Voltage Directive 2006/95/EC Touch Current measured in accordance with IEC 60990 using measuring network Figure 3 (VIA PFM only) Pending EMI/EMC Compliance FCC Part 15, EN55022, CISPR22: 2006 + A1: 2007, Conducted Emissions Class B Limits - with –OUT connected to GND EN61000-3-2: 2009, Harmonic Current Emissions Class A VIA PFM™ Family Rev 1.0 vicorpower.com Page 13 of 22 04/2015 800 927.9474 0.5 mA PFA175x240x400Axx General Characteristics (Cont.) Specifications apply over all line and load conditions, 50 Hz and 60 Hz line frequencies, TC = 25°C, unless otherwise noted. Boldface specifications apply over the temperature range of the specified Product Grade. Attribute Symbol Conditions / Notes Min Pending EMI/EMC Compliance (cont.) EN61000-3-3: 2005, Voltage Changes & Flicker PST <1.0; PLT <0.65; dc <3.3% dmax <6% EN61000-4-4: 2004, Electrical Fast Transients Level 2, Performance Criteria A EN61000-4-5: 2006, Surge Immunity Level 3, Immunity Criteria A, external TMOV required EN61000-4-6: 2009, Conducted RF Immunity Level 2, 130 dBµV (3.0 VRMS) EN61000-4-8: 1993 + A1 2001, Power Frequency H-Field 10A/m, continuous field Level 3, Performance Criteria A EN61000-4-11: 2004, Voltage Dips & Interrupts Class 2, Performance Criteria A Dips, Performance Criteria B Interrupts VIA PFM™ Family Rev 1.0 vicorpower.com Page 14 of 22 04/2015 800 927.9474 Typ Max Unit PFA175x240x400Axx Product Details and Design Guidelines Input Fuse Selection VI Brick products are not internally fused in order to provide flexibility in configuring power systems. Input line fusing is recommended at system level, in order to provide thermal protection in case of catastrophic failure. The fuse shall be selected by closely matching system requirements with the following characteristics: Building Blocks and System Designs +IN ~ + ~ – Recommended fuse: 8 A, 216 Series Littelfuse or lower current rating +OUT (usually greater than the VIA PFM maximum current at lowest input voltage) Maximum voltage rating (usually greater than the maximum possible input voltage) VIA PFM™ MOV -IN -OUT Holdup Capacitor Ambient temperature Breaking capacity per application requirements Nominal melting I2t Figure 21 – 400 W Universal AC-to-DC Supply The VIA PFM is a high efficiency AC-to-DC converter, operating from a universal AC input to generate an isolated SELV24 VDC output bus with power factor correction. It is the key component of an AC-to-DC power supply system such as the one shown in Figure 21 above. The input to the VIA PFM is a rectified sinusoidal AC source with a power factor maintained by the module with harmonics conforming to IEC 61000-3-2. Internal filtering enables compliance with the standards relevant to the application (Surge, EMI, etc.). See EMI/EMC Compliance standards on Page 13. The module uses secondary-side energy storage (at the SELV 24 V bus) to maintain output hold up through line dropouts and brownouts. Downstream regulators also provide tighter voltage regulation, if required. Traditional PFC Topology Full Wave Rectifier EMI/TVS Filter Isolated DC / DC 24 V Bus Converter Figure 22 – Traditional PFC AC-to-DC supply To cope with input voltages across worldwide AC mains (85 – 264 Vac), traditional AC-DC power supplies (Figure 22) use two power conversion stages: 1) a PFC boost stage to step up from a rectified input as low as 85 Vac to ~380 Vdc; and 2) a DC-DC down converter from 380 Vdc to a 24 V bus. Fault Handling Input Undervoltage (UV) Fault Protection The input voltage is monitored by the micro-controller to detect an input under voltage condition. When the input voltage is less than the VIN-UVLO-, a fault is detected, the fault latch and reset logic disables the modulator, the modulator stops powertrain switching, and the output voltage of the unit falls. After a time tUVLO, the unit shuts down. Faults lasting less than tUVLO may not be detected. Such a fault does not go through an auto-restart cycle. Once the input voltage rises above VINUVLO+, the unit recovers from the input UV fault, the powertrain resumes normal switching after a time tON and the output voltage of the unit reaches the set-point voltage within a time tSS. Overcurrent (OC) Fault Protection The unit’s output current, determined by VEAO, VIN_B and the primaryside sensed output voltage is monitored by the microcontroller to detect an output OC condition. If the output current exceeds its current limit, a fault is detected, the reset logic disables the modulator, the modulator stops powertrain switching, and the output voltage of the module falls after a time tOC. As long as the fault persists, the module goes through an auto-restart cycle with off time equal to tOFF + tON and on time equal to tOC. Faults shorter than a time tOC may not be detected. Once the fault is cleared, the module follows its normal start up sequence after a time tOFF. Short Circuit (SC) Fault Protection The microcontroller determines a short circuit on the output of the unit by measuring its primary sensed output voltage and EAO. Most commonly, a drop in the primary-sensed output voltage triggers a short circuit event. The module responds to a short circuit event within a time tSC. The module then goes through an auto restart cycle, with an off time equal to tOFF + tON and an on time equal to tSC, for as long as the short circuit fault condition persists. Once the fault is cleared, the unit follows its normal start up sequence after a time tOFF. Faults shorter than a time tSC may not be detected. The efficiency of the boost stage and of traditional power supplies is significantly compromised operating from worldwide AC lines as low as 85 Vac. Adaptive Cell™ Topology With its single stage Adaptive Cell™ topology, the VIA PFM enables consistently high efficiency conversion from worldwide AC mains to a 24 V bus and efficient secondary-side power distribution. VIA PFM™ Family Rev 1.0 vicorpower.com Page 15 of 22 04/2015 800 927.9474 PFA175x240x400Axx Temperature Fault Protection The microcontroller monitors the temperature within the VIA PFM. If this temperature exceeds TJ-OTP+, an overtemperature fault is detected, the reset logic block disables the modulator, the modulator stops the powertrain switching and the output voltage of the VIA PFM falls. Once the case temperature falls below TCASE-OTP-, after a time greater than or equal to tOFF, the converter recovers and undergoes a normal restart. For the C-grade version of the converter, this temperature is 75°C. Faults shorter than a time tOTP may not be detected. If the temperature falls below TCASE-UTP-, an undertemperature fault is detected, the reset logic disables the modulator, the modulator stops powertrain switching and the output voltage of the unit falls. Once the case temperature rises above TCASEUTP, after a time greater than or equal to tOFF, the unit recovers and undergoes a normal restart. Output Overvoltage Protection (OVP) The microcontroller monitors the primary sensed output voltage to detect output OVP. If the primary sensed output voltage exceeds VOUTOVLO+, a fault is latched, the logic disables the modulator, the modulator stops powertrain switching, and the output voltage of the module falls after a time tSOVP. Faults shorter than a time tSOVP may not be detected. This type of fault is a latched fault and requires that 1) the EN pin be toggled or 2) the input power be recycled to recover from the fault. Hold-up Capacitance The VI Brick AC Front End uses secondary-side energy storage (at the SELV 24 V bus) and optional PRM® regulators to maintain output hold up through line dropouts and brownouts. The module’s output bulk capacitance can be sized to achieve the required hold up functionality. Hold-up time depends upon the output power drawn from the VI Brick AC Front End based AC-to-DC front end and the input voltage range of downstream DC-to-DC converters. The following formula can be used to calculate hold-up capacitance for a system comprised of VI Brick AC Front End and a downstream regulator: Output Filtering 2 2 C = 2*POUT*(0.005+td) / (V2 – V1 ) where: C VIA PFM’s output bulk capacitance in farads td Hold-up time in seconds POUT VIA PFM’s output power in watts V2 Output voltage of VIA PFM’s converter in volts Downstream regulator undervoltage turn off (volts) V1 The output voltage has the following two components of voltage ripple: 1) Line frequency voltage ripple: 2*fLINE Hz component 2) Switching frequency voltage ripple: 1 MHz module switching frequency component (see Figure 5). Line Frequency Filtering Output line frequency ripple depends upon output bulk capacitance. Output bulk capacitor values should be calculated based on line frequency voltage ripple. High-grade electrolytic capacitors with adequate ripple current ratings, low ESR and a minimum voltage rating of 35 V are recommended. lPK lPK/2 loutDC lfLINE Figure 23 – Output current waveform Based on the output current waveform, as seen in Figure 23, the following formula can be used to determine peak-to-peak line frequency output voltage ripple: VPPl ~ = 0.2 * POUT / (VOUT * fLINE * C) where: VPPl Output voltage ripple Peak-to-peak line frequency POUT Average output power VOUT Output voltage set point, nominally 24 V fLINE Frequency of line voltage C Output bulk capacitance IDC Maximum average output current IPK Peak-to-peak line frequency output current ripple In certain applications, the choice of bulk capacitance may be determined by hold-up requirements and low frequency output voltage filtering requirements. Such applications may use the greater capacitance value determined from these requirements. The ripple current rating for the bulk capacitors can be determined from the following equation: –OR– Iripple POUT / IOUT-PK, whichever is greater. The VIA PFM requires an output bulk capacitor in the range of 27,000 μF to 60,000 μF for proper operation of the PFC front-end. A minimum 40,000 μF is recommended for full rated output. Capacitance can be reduced proportionally for lower maximum loads. ~ = 0.8 * POUT / VOUT Switching Frequency Filtering This is included within the VIA PFM. No external filtering is necessary for most applications. For the most noise sensitive applications, a common mode choke followed by two caps to PE GND will reduce switching noise further. VIA PFM™ Family Rev 1.0 vicorpower.com Page 16 of 22 04/2015 800 927.9474 PFA175x240x400Axx EMI Filtering and Transient Voltage Suppression EMI Filtering The VI Brick AC® Front End with PFC is designed such that it will comply with EN55022 Class B for Conducted Emissions with a commercially available off-the-shelf EM filter. The emissions spectrum is shown in Figures 13 - 16. If one of the outputs is connected to earth ground, a small output common mode choke is also recommended. + TC_BOT EMI performance is subject to a wide variety of external influences such as PCB construction, circuit layout etc. As such, external components in addition to those listed herein may be required in specific instances to gain full compliance to the standards specified. Transient Voltage Suppression The VIA PFM contains line transient suppression circuitry to meet specifications for surge (i.e. EN61000-4-5) and fast transient conditions (i.e. EN61000-4-4 fast transient/“burst”). Thermal Considerations The VIA package provides effective conduction cooling from either of the two module surfaces. Heat may be removed from the top surface, the bottom surface or both. The extent to which these two surfaces are cooled is a key component for determining the maximum power that can be processed by a VIA, as can be seen from specified thermal operating area on Page 4. Since the VIA has a maximum internal temperature rating, it is necessary to estimate this internal temperature based on a system-level thermal solution. To this purpose, it is helpful to simplify the thermal solution into a roughly equivalent circuit where power dissipation is modeled as a current source, isothermal surface temperatures are represented as voltage sources and the thermal resistances are represented as resistors. Figure 24 shows the “thermal circuit” for the VIA module. + RJC_TOP TC_TOP – RHOU – RJC_BOT PDISS s TC_BOT + – RJC s PDISS s Figure 25 – Single-sided cooling VIA thermal model In this case, RJC can be derived as following: RJC = (RJC_TOP + RHOU) • RJC_BOT RJC_TOP + RHOU + RJC_BOT Double side cooling: while this option might bring limited advantage to the module internal components (given the surface-tosurface coupling provided), it might be appealing in cases where the external thermal system requires allocating power to two different elements, like for example heatsinks with independent airflows or a combination of chassis/air cooling. Powering a Constant Power Load When the output voltage of the VIA PFM module is applied to the input of the downstream regulator, the regulator turns on and acts as a constant-power load. When the module’s output voltage reaches the input undervoltage turn on of the regulator, the regulator will attempt to start. However, the current demand of the downstream regulator at the undervoltage turn-on point and the hold-up capacitor charging current may force the VIA PFM into current limit. In this case, the unit may shut down and restart repeatedly. In order to prevent this multiple restart scenario, it is necessary to delay enabling a constant-power load when powered up by the upstream VIA PFM until after the output set point of the VIA PFM is reached. This can be achieved by s 1. keeping the downs- sequence Figure 24 – Double sided cooling VIA thermal model In this case, the internal power dissipation is PDISS, RJC_TOP and RJC_BOT are thermal resistance characteristics of the VIA module and the top and bottom surface temperatures are represented as TC_TOP, and TC_BOT. It interesting to notice that the package itself provides a high degree of thermal coupling between the top and bottom case surfaces (represented in the model by the resistor RHOU). This feature enables two main options regarding thermal designs: Single side cooling: the model of Figure 1 can be simplified by calculating the parallel resistor network and using one simple thermal resistance number and the internal power dissipation curves; an example for bottom side cooling only is shown in Figure 25. and 2. turning the downstream constant-power load on after the output voltage of the module reaches 24 V steady state After the initial startup, the output of the VIA PFM can be allowed to fall to 15 V during a line dropout at full load. In this case, the circuit should not disable the downstream regulator if the input voltage falls after it is turned on; therefore, some form of hysteresis or latching is needed on the enable signal for the constant power load. The output capacitance of the VIA PFM should also be sized appropriately for a constant power load to prevent collapse of the output voltage of the module during line dropout (see Hold up Capacitance on Page 16). A constant-power load can be turned off after completion of the required hold up time during the power-down sequence or can be allowed to turn off when it reaches its own undervoltage shutdown point. VIA PFM™ Family Rev 1.0 vicorpower.com Page 17 of 22 04/2015 800 927.9474 PFA175x240x400Axx The timing diagram in Figure 26 shows the output voltage of the VIA PFM and the downstream regulator’s enable pin voltage and output voltage of the PRM regulator for the power up and power down sequence. It is recommended to keep the time delay approximately 10 to 20 ms. VI BRICK™ AC Front End When the VIA assembly is complete the Reinforced Insulation can only be tested at Basic Insulation values as specified in the electric strength Test Procedure noted in clause 5.2.2 of IEC 60950-1. Test Procedure Note from IEC 60950-1 “For equipment incorporating both REINFORCED INSULATION and lower grades of insulation, care is taken that the voltage applied to the REINFORCED INSULATION does not overstress BASIC INSULATION or SUPPLEMENTARY INSULATION.” 24V – 3% VOUT PRM UV Turn on Summary Downstream Regulator tDELAY The final VIA assembly contains basic insulation from input to case, reinforced insulation from input to output, and functional insulation from output to case. Enable Downstream Regulator VOUT tHOLD-UP Figure 26 – PRM Enable Hold off Waveforms Special care should be taken when enabling the constant-power load near the auto-ranger threshold, especially with an inductive source upstream of the VIA PFM. A load current spike may cause a large input voltage transient, resulting in a range change which could temporarily reduce the available power (see Adaptive Cell™ Topology below). The output of the VIA complies with the requirements of SELV circuits so only functional insulation is required from the output (SELV) to case (PE) because the case is required to be connected to protective earth in the final installation. The construction of the VIA can be summarized by describing it as a “Class II” component installed in a “Class I” subassembly. The reinforced insulation from input to output can only be tested at basic insulation values on the completely assembled VIA product. VI ChiP Isolation Adaptive Cell™ Topology The Adaptive Cell topology utilizes magnetically coupled “top” and “bottom” primary cells that are adaptively configured in series or parallel by a configuration controller comprised of an array of switches. A microcontroller monitors operating conditions and defines the configuration of the top and bottom cells through a range control signal. Input Output SELV A comparator inside the microcontroller monitors the line voltage and compares it to an internal voltage reference. If the input voltage of the VI Brick AC Front End crosses above the positive going cell reconfiguration threshold voltage, the top cell and bottom cell configure in series and the unit operates in “high” range. RI Figure 27 – VI Chip before final assembly in the VIA If the peak of input voltage of the unit falls below the negative-going range threshold voltage for two line cycles, the cell configuration controller configures the top cell and bottom cell in parallel, the unit operates in “low” range. Power processing is held off while transitioning between ranges and the output voltage of the unit may temporarily droop. External output hold up capacitance should be sized to support power delivery to the load during cell reconfiguration. The minimum specified external output capacitance is sufficient to provide adequate ride-through during cell reconfiguration for typical applications. Waveforms showing active cell reconfiguration can be seen in Figure 9. VIA PFM Isolation VI ChiP Input Output VIA Input Circuit Dielectric Withstand SELV VIA Output Circuit RI The chassis of the VIA PFM is required to be connected to Protective Earth when installed in the end application and must satisfy the requirements of IEC 60950-1 for Class I products. The VIA PFM contains an internal safety approved isolating component (VI ChiP) that provides the Reinforced Insulation from Input to Output. The isolating component is individually tested for Reinforced Insulation from Input to Output at 3000 Vac or 4242 Vdc prior to the final assembly of the VIA. BI PE Figure 28 – PFM VIA after final assembly VIA PFM™ Family Rev 1.0 vicorpower.com Page 18 of 22 04/2015 800 927.9474 FI PFA175x240x400Axx VIA PFM Chassis Mount Package Mechanical Drawing C .37 9.30 A .152 3.861 THRU TYP B .11 2.90 3 1 OUTPUT INSERT (41817) TO BE REMOVED PRIOR TO USE INPUT INSERT (41816) TO BE REMOVED PRIOR TO USE 2 1.171 29.750 4 86(7<&2/8*25 (48,9)25287387&211(&7,21 86(7<&2/8*25 (48,9)25,1387&211(&7,21 NOTES: 1- RoHS COMPLIANT PER CST-0001 LATEST REVISION. 2- SEE PRODUCT DATA SHEET FOR PIN DESIGNATIONS. PRODUCT 125 mm VIA PFM DIM 'A' >@ DIM 'B' >@ DIM 'C' >@ Product outline drawing; Product outline drawings are available in .pdf and .dxf formats. 3D mechanical models are available in .pdf and .step formats. See www.vicorpower.com/ac-dc-converters-board-mount/ac-front-end-module for more details. VIA PFM™ Family Rev 1.0 vicorpower.com Page 19 of 22 04/2015 800 927.9474 1.40 35.54 PFA175x240x400Axx VIA PFM PCB Mount Package Mechanical Drawing and Recommended Land Pattern .474 12.029 .70 17.77 0 F E D C .152 3.861 THRU, TYP 0 B A .586 14.875 1 3 0 0 4 2 .429 10.905 0 .586 14.875 0 .474 12.029 .429 10.905 TOP VIEW BOTTOM VIEW (COMPONENT SIDE) L .37 9.30 SEATING PLANE .170±.003 4.318±.076 PLATED THRU .015 [.381] ANNULAR RING (2) PL. F ±.003 [.076] 0 D ±.003 [.076] .100±.003 2.540±.076 PLATED THRU .015 [.381] ANNULAR RING (2) PL. E ±.003 [.076] .150 3.810 (2) PL. C ±.003 [.076] .080 2.032 (2) PL. 1.40 35.54 .586±.003 14.875±.076 .474±.003 12.029±.076 2 4 1 3 .429±.003 10.905±.076 0 .172±.003 4.370±.076 PLATED THRU .064 [1.626] ANNULAR RING TYP .429±.003 10.905±.076 .586±.003 14.875±.076 0 .474±.003 12.029±.076 0 RECOMMENDED HOLE PATTERN (COMPONENT SIDE) NOTES: 1- RoHS COMPLIANT PER CST-0001 LATEST REVISION. 2- SEE PRODUCT DATA SHEET FOR PIN DESIGNATIONS. PRODUCT DIM 'A' DIM 'B' DIM 'C' DIM 'D' DIM 'E' DIM 'F' 125 mm VIA PFM 2.18 [55.27] 4.35 [110.55] 2.004 [50.903] .565 [14.350] 1.192 [30.275] 1.953 [49.614] VIA PFM™ Family Rev 1.0 vicorpower.com Page 20 of 22 04/2015 800 927.9474 DIM 'L' .103 [2.607] LONG .182 [4.614] EXTRA LONG PFA175x240x400Axx Revision History Revision Date 1.0 04/01/15 Description Intital release Page Number(s) n/a VIA PFM™ Family Rev 1.0 vicorpower.com Page 21 of 22 04/2015 800 927.9474 PFA175x240x400Axx Vicor’s comprehensive line of power solutions includes high density AC-DC and DC-DC modules and accessory components, fully configurable AC-DC and DC-DC power supplies, and complete custom power systems. Information furnished by Vicor is believed to be accurate and reliable. However, no responsibility is assumed by Vicor for its use. Vicor makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication. Vicor reserves the right to make changes to any products, specifications, and product descriptions at any time without notice. Information published by Vicor has been checked and is believed to be accurate at the time it was printed; however, Vicor assumes no responsibility for inaccuracies. Testing and other quality controls are used to the extent Vicor deems necessary to support Vicor’s product warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. Specifications are subject to change without notice. Vicor’s Standard Terms and Conditions All sales are subject to Vicor’s Standard Terms and Conditions of Sale, which are available on Vicor’s webpage or upon request. Product Warranty In Vicor’s standard terms and conditions of sale, Vicor warrants that its products are free from non-conformity to its Standard Specifications (the “Express Limited Warranty”). This warranty is extended only to the original Buyer for the period expiring two (2) years after the date of shipment and is not transferable. UNLESS OTHERWISE EXPRESSLY STATED IN A WRITTEN SALES AGREEMENT SIGNED BY A DULY AUTHORIZED VICOR SIGNATORY, VICOR DISCLAIMS ALL REPRESENTATIONS, LIABILITIES, AND WARRANTIES OF ANY KIND (WHETHER ARISING BY IMPLICATION OR BY OPERATION OF LAW) WITH RESPECT TO THE PRODUCTS, INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OR REPRESENTATIONS AS TO MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, INFRINGEMENT OF ANY PATENT, COPYRIGHT, OR OTHER INTELLECTUAL PROPERTY RIGHT, OR ANY OTHER MATTER. This warranty does not extend to products subjected to misuse, accident, or improper application, maintenance, or storage. Vicor shall not be liable for collateral or consequential damage. 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Life Support Policy VICOR’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF VICOR CORPORATION. As used herein, life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. Per Vicor Terms and Conditions of Sale, the user of Vicor products and components in life support applications assumes all risks of such use and indemnifies Vicor against all liability and damages. Intellectual Property Notice Vicor and its subsidiaries own Intellectual Property (including issued U.S. and Foreign Patents and pending patent applications) relating to the products described in this data sheet. No license, whether express, implied, or arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Interested parties should contact Vicor's Intellectual Property Department. The products described on this data sheet are protected by the following U.S. Patents Numbers: Patents Pending. Vicor Corporation 25 Frontage Road Andover, MA, USA 01810 Tel: 800-735-6200 Fax: 978-475-6715 email Customer Service: [email protected] Technical Support: [email protected] VIA PFM™ Family Rev 1.0 vicorpower.com Page 22 of 22 04/2015 800 927.9474