BCM® Bus Converter BCM384x480y325Bzz S ® US C C NRTL US Isolated Fixed Ratio DC-DC Converter Features & Benefits Product Ratings • 384VDC – 48VDC 325W Bus Converter VIN = 384V (360 – 400V) POUT = up to 325W • High efficiency (95%) reduces system power consumption VOUT = 48V (45 – 50V) (no load) K = 1/8 • High power density (1106W/in3) reduces power system footprint by >40% Description • Contains built-in protection features: n Undervoltage n Overvoltage Lockout n Overcurrent Protection n Short circuit Protection n Overtemperature Protection The VI Chip® bus converter is a high efficiency (95%) Sine Amplitude Converter™ (SAC™) operating from a 360 to 400VDC primary bus to deliver an isolated, ratiometric output voltage from 45 to 50VDC. The Sine Amplitude Converter offers a low AC impedance beyond the bandwidth of most downstream regulators; therefore capacitance normally at the load can be located at the input to the Sine Amplitude Converter. Since the transformation ratio of the BCM384x480y325Bzz is 1/8, the capacitance value can be reduced by a factor of 64x, resulting in savings of board area, materials and total system cost. • Provides enable/disable control, internal temperature monitoring • Can be paralleled to create multi-kW arrays The BCM384F480y325Bzz is provided in a VI Chip package compatible with standard pick-and-place and surface mount assembly processes. The co-molded VI Chip package provides enhanced thermal management due to a large thermal interface area and superior thermal conductivity. The high conversion efficiency of the BCM384x480y325Bzz increases overall system efficiency and lowers operating costs compared to conventional approaches. Typical Applications • High End Computing Systems • Automated Test Equipment • High Density Power Supplies • Communications Systems Typical Application BCM TM PC SW1 enable/disable switch F1 VIN +IN +OUT –IN –OUT COUT CIN GND PRIMARY SECONDARY ISOLATION BOUNDRY BCM® Bus Converter Page 1 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 POL BCM384x480y325Bzz Typical Application PRM BCM ENABLE enable/disable switch TM PC SGND enable/disable switch R FUSE V C IN +IN +OUT –IN –OUT I_BCM_ELEC PRIMARY SOURCE_RTN VAUX R R TRIM_PRM VTM REF/ REF_EN TRIM AL VT SHARE/ CONTROL NODE VC AL_PRM TM VTM Start Up Pulse +OUT PC C R O_PRM_DAMP SGND I_PRM_FLT R +IN +OUT –IN –OUT L I_PRM_CER SGND LOAD O_VTM_CER +IN O_PRM_FLT C O_PRM_CER –IN –OUT PRIMARY SECONDARY SECONDARY LOAD_RTN ISOLATION BOUNDRY ISOLATION BOUNDRY SGND BCM384x480y325Bzz + PRM + VTM, Adaptive Loop Configuration V TM enable/disable switch VAUX/SER-IN FUSE VIN SOURCE_RTN C I_BCM_ELEC +IN +OUT –IN –OUT VT SHARE/ CONTROL NODE VC IFB I_PRM_DAMP L I_PRM_FLT PRIMARY AL SGND R IN Voltage Sense and Error Amplifier (Differential) GND VTM SGND VTM Start up Pulse V+ +IN +OUT –IN –OUT SGND External Current Sense I_PRM_ELEC SGND R L C O_PRM_DAMP +IN O_PRM_FLT C O_PRM_CER –IN –OUT PRIMARY SECONDARY SECONDARY ISOLATION BOUNDRY ISOLATION BOUNDRY SGND BCM384x480y325Bzz + PRM + VTM, Remote Sense Configuration BCM® Bus Converter Page 2 of 22 VC PC V– VOUT –IN +OUT TM Voltage Reference with Soft Start +IN C SGND OUT REF/ REF_EN TRIM SGND REF 3312 VAUX ENABLE enable/disable switch PC REF SGND PRM Rev 1.1 10/2016 Voltage Sense BCM OUT VC IFB I_PRM_DAMP L V Adaptive Loop Temperature Feedback vicorpower.com 800 927.9474 O_VTM_CER LOAD BCM384x480y325Bzz Pin Configuration 4 3 2 1 A A +OUT B B C C D D E E -OUT F G H H J J +OUT -OUT +IN K K L L M M N N P P R R TM RSV PC -IN T T Bottom View Pin Descriptions Pin Number Signal Name Type Function A1-E1, A2-E2 +IN INPUT POWER Positive input power terminal L1-T1, L2-T2 –IN INPUT POWER RETURN Negative input power terminal H1, H2 TM OUTPUT J1, J2 RSV NC Temperature monitor, input side referenced signal No connect K1, K2 PC OUTPUT/INPUT A3-D3, A4-D4, J3-M3, J4-M4 +OUT OUTPUT POWER Positive output power terminal E3-H3, E4-H4, N3-T3, N4-T4 –OUT OUTPUT POWER RETURN Negative output power terminal BCM® Bus Converter Page 3 of 22 Rev 1.1 10/2016 Enable and disable control, input side referenced signal vicorpower.com 800 927.9474 BCM384x480y325Bzz Part Ordering Information Device Input Voltage Range Package Type Output Voltage x 10 Temperature Grade BCM 384 x 480 y BCM = BCM 384 = 360 – 400V F = Full VIC SMD Output Power Revision 325 B 325 = 325W B T = -40 – 125ºC zz 00 = standard 480 = 48V T = Full VIC TH Version M = -55 – 125ºC >00 = Customer specific version Standard Models Part Number BCM384F480T325B00 BCM384F480M325B00 BCM384T480T325B00 BCM384T480M325B00 VIN Package Type VOUT Temperature 360 – 400V Full VIC SMD 48V (45 – 50V) -40 – 125ºC 360 – 400V Full VIC TH 48V (45 – 50V) -40 – 125ºC -55 – 125ºC -55 – 125ºC Power Version 325W 00 = standard 325W 00 = standard 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 +IN to –IN VIN slew rate Min Max -1 440 V 1 V / µs 4242 V 60 V 10.5 A 7.05 A Operational Isolation voltage, input to ouput +OUT to –OUT Output current transient -1 ≤ 1ms, ≤ 10% DC Output current average Unit PC to –IN -0.3 20 V TM to –IN -0.3 7 V Operating IC junction temperature T–Grade -40 125 ºC Storage temperature T–Grade -40 125 ºC BCM® Bus Converter Page 4 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz Electrical Specifications Specifications apply over all line and load conditions, unless otherwise noted; boldface specifications apply over the temperature range of -40°C ≤ TCASE ≤ 100°C (T-Grade); all other specifications are at TCASE = 25ºC unless otherwise noted. Attribute Symbol Conditions / Notes Min Typ Max Unit 400 V 1.2 mA 620 ms Powertrain Input voltage range, continuous 360 VIN_DC Quiescent current IQ VIN to VOUT time TON1 Disabled, PC Low 1 VIN = 384V, PC floating VIN = 384V, TCASE = 25ºC No load power dissipation PNL 7.2 3 VIN = 384V 12 VIN = 360V to 400V 15 Inrush current peak IINR_P DC input current IIN_DC At POUT = 325W K 18 VIN = 360V to 400V, TCASE = 25ºC Worse case of: VIN = 400V, COUT = 100μF, RLOAD = 7Ω Transformation ratio 10 2 K = VOUT / VIN, at no load W 4 A 0.9 A 1/8 V/V Output power (average) POUT_AVG IOUT_AVG ≤ 7.05A 325 W Output power (peak) POUT_PK 1ms max, POUT_AVG ≤ 325W 450 W Output current (average) IOUT_AVG POUT_AVG ≤ 325W 7.05 A Output current (peak) IOUT_PK 1ms max, IOUT_AVG ≤ 7.05A 10.5 A VIN = 384V, IOUT = 7.05A; TCASE = 25°C Efficiency (ambient) hAMB 95.0 VIN = 360V to 400V, IOUT = 7.05A; TCASE = 25°C 94.9 VIN = 384V, IOUT = 3.53A; TCASE = 25°C 93.5 94.9 95.4 Efficiency (hot) hHOT VIN = 384V, IOUT = 7.05A; TCASE = 100°C 94.3 Efficiency (over load range) h20% 1.41A < IOUT < 7.05A 80.0 Output resistance 96.0 % % % ROUT_COLD IOUT = 7.05A, TCASE = -40°C 60 100 130 ROUT_AMB IOUT = 7.05A, TCASE = 25°C 110 135 150 ROUT_HOT IOUT = 7.05A, TCASE = 100°C 130 165 260 1.56 1.65 1.73 MHz 400 mV mΩ Switching frequency FSW Output voltage ripple VOUT_PP COUT = 0F, IOUT = 7.05A, VIN = 384V, 20MHz BW 200 Input inductance (parasitic) LIN_PAR Simulated J-lead model 5.6 nH Frequency up to 30MHz, Simulated J-lead model 600 pH CIN_INT Effective value at 384VIN 0.1 µF Output capacitance (internal) COUT_INT Effective value at 48VOUT 5.6 µF Output capacitance (external) COUT_EXT Output inductance (parasitic) LOUT_PAR Input capacitance (internal) BCM® Bus Converter Page 5 of 22 0 Rev 1.1 10/2016 vicorpower.com 800 927.9474 100 µF BCM384x480y325Bzz Electrical Specifications (Cont.) Specifications apply over all line and load conditions, unless otherwise noted; boldface specifications apply over the temperature range of -40°C ≤ TCASE ≤ 100°C (T-Grade); all other specifications are at TCASE = 25ºC unless otherwise noted. Attribute Symbol Conditions / Notes Min Typ Max Unit VIN_OVLO+ 410 429 440 V 401 420 435 V Protection Input overvoltage lockout threshold Input overvoltage recovery threshold VIN_OVLO- Input overvoltage lockout hysteresis VIN_OVLO_HYST 9 V Overvoltage lockout response time TOVLO 47 µs TAUTO_RESTART 460 540 620 ms Input undervoltage lockout threshold VIN_UVLO- 270 293 315 V Input undervoltage recovery threshold VIN_UVLO+ 285 308 330 V Input undervoltage lockout hysteresis VIN_UVLO_HYST 15 V TUVLO 47 µs Fault recovery time Undervoltage lockout response time Output overcurrent trip threshold IOCP Output overcurrent response time constant TOCP Short circuit protection trip threshold ISCP Short circuit protection response time TSCP Thermal shutdown threshold 7.3 Effective internal RC filter 11 14 A 4.0 ms 14 A 1 µs 125 TJ_OTP °C 12 500 450 Output Power (W) 350 8 300 6 250 200 4 150 100 2 50 0 0 43.3 44.1 45.0 45.8 46.6 47.5 48.3 49.2 Output Voltage (V) P (ave) I (ave) p (pk), ≤ 1ms I (pk), ≤ 1ms Figure 1 — Safe operating area BCM® Bus Converter Page 6 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 50.0 50.8 Output Current (A) 10 400 BCM384x480y325Bzz Signal Characteristics Specifications apply over all line and load conditions, unless otherwise noted; boldface specifications apply over the temperature range of -40°C ≤ TCASE ≤ 100°C (T-Grade); all other specifications are at TCASE = 25ºC unless otherwise noted. Primary Control: PC • The PC pin enables and disables the BCM. When held low, the BCM is disabled. • In an array of BCM modules, PC pins should be interconnected to synchronize start up and permit start up into full load conditions. • PC pin outputs 5V during normal operation. PC pin internal bias level drops to 2.5V during fault mode, provided VIN remains in the valid range. SIGNAL TYPE STATE Regular Operation ANALOG OUTPUT Standby Transition SYMBOL TYP MAX UNIT VPC 4.7 5.0 5.3 V 2.0 3.5 5.0 mA PC source (current) IPC_EN 50 100 PC resistance (internal) RPC_INT Internal pull down resistor 50 150 PC capacitance (internal) CPC_INT To permit regular operation 60 RPC_S Start Up PC time to start TON1 Transition MIN IPC_OP PC load resistance Standby CONDITIONS / NOTES PC available current PC voltage Start Up Regular Operation DIGITAL INPUT / OUTPUT ATTRIBUTE PC enable threshold VPC_EN PC disable threshold VPC_DIS PC disable duration TPC_DIS_T PC threshold hysteresis VPC_HYSTER PC enable to VOUT time TON2 PC disable to standby time TPC_DIS PC fault response time TFR_PC µA 400 1000 2.0 Minimum time before attempting re-enable 2.5 620 ms 3.0 V 1.95 V 1 50 From fault to PC = 2V pF kΩ s 50 VIN = 384V for at least TON1 ms kΩ mV 100 150 µs 4 10 µs 100 µs Temperature Monitor: TM • The TM pin monitors the internal temperature of the controller IC within an accuracy of ±5°C. • Can be used as a “Power Good” flag to verify that the BCM module is operating. • Is used to drive the internal comparator for Overtemperature Shutdown. SIGNAL TYPE STATE ATTRIBUTE TM voltage range TM voltage reference ANALOG OUTPUT DIGITAL INPUT / OUTPUT Regular Operation Transition Standby SYMBOL CONDITIONS / NOTES TM available current ITM TM gain ATM TM voltage ripple VTM_PP TM capacitance (external) CTM_EXT TM fault response time TFR_TM TM voltage VTM_DIS TM pull down (internal) RTM_INT TJ controller = 27°C 3.00 UNIT 4.04 V 3.05 V 100 CTM = 0pF, VIN = 352V, IOUT = 28.5A 120 From fault to TM = 1.5V 200 mV 50 pF 10 vicorpower.com 800 927.9474 25 40 µA mV/°C µs 0 Internal pull down resistor Reserved for factory use. No connection should be made to this pin. Rev 1.1 10/2016 2.95 MAX 10 Reserved: RSV BCM® Bus Converter Page 7 of 22 TYP 2.12 VTM VTM_AMB MIN V 50 kΩ BCM® Bus Converter Page 8 of 22 NL 5V 2.5 V 5V 3V PC VUVLO+ VUVLO– Rev 1.1 10/2016 vicorpower.com 800 927.9474 1 A E: TON2 F: TOCP G: TPC–DIS H: TSCP** B D 1: Controller start 2: Controller turn off 3: PC release C *Min value switching off **From detection of error to power train shut down A: TON1 B: TOVLO* C: TAUTO_RESTART D:TUVLO 0.4 V 3 V @ 27°C TM LL • K VOUT C 500mS before retrial 3V VIN VOVLO+ VOVLO– 2 F 4: PC pulled low 5: PC released on output SC 6: SC removed IOCP ISSP IOUT E 3 G 4 Notes: H 5 – Timing and signal amplitudes are not to scale – Error pulse width is load dependent 6 BCM384x480y325Bzz Timing Diagram BCM384x480y325Bzz Application Characteristics 14 97.0 13 Full Load Efficiency (%) No Load Power Dissipation (W) The following values, typical of an application environment, are collected at TCASE = 25ºC unless otherwise noted. See associated figures for general trend data. 12 11 10 9 8 7 6 5 4 360 364 368 372 376 380 384 388 392 396 96.5 96.0 95.5 95.0 94.5 94.0 -55 400 -35 -15 Input Voltage (V) TCASE: -40ºC 25ºC VIN_DC: 100ºC Figure 2 — No load power dissipation vs. Vin 18 Power Dissipation (W) 20 97 Efficiency (%) 94 91 88 85 82 79 76 73 0.0 0.8 1.6 2.4 3.2 4.0 4.8 360V 5.6 6.4 7.2 384V 4 2 0.0 0.8 1.6 Power Dissipation (W) Efficiency (%) 85 82 79 76 73 4.8 5.6 6.4 4.8 5.6 6.4 360V 384V 7.2 8.0 7.2 8.0 400V 7.2 8.0 14 12 10 8 6 4 2 0 0.0 0.8 1.6 384V 2.4 3.2 4.0 4.8 5.6 6.4 Output Current (A) 400V Figure 6 — Efficiency at TCASE = 25°C BCM® Bus Converter Page 9 of 22 4.0 16 Output Current (A) 360V 3.2 Figure 5 — Power dissipation at TCASE = -40°C 88 VIN_DC: 2.4 VIN_DC: 400V 91 4.0 400V 6 18 3.2 384V Output Current (A) 94 2.4 360V 8 20 1.6 105 10 97 0.8 85 12 100 0.0 65 14 0 8.0 Figure 4 — Efficiency at TCASE = -40°C 70 45 16 Output Current (A) VIN_DC: 25 Figure 3 — Full load efficiency vs. temperature; Vin 100 70 5 Case Temperature (ºC) VIN_DC: 360V 384V Figure 7 — Power dissipation at TCASE = 25°C Rev 1.1 10/2016 vicorpower.com 800 927.9474 400V BCM384x480y325Bzz Application Characteristics (Cont.) 20 97 18 Power Dissipation (W) 100 Efficiency (%) 94 91 88 85 82 79 76 73 70 0.0 0.8 1.6 2.4 3.2 4.0 4.8 5.6 6.4 7.2 16 14 12 10 8 6 4 2 0 8.0 0.0 0.8 1.6 360V 384V VIN_DC: 400V Figure 8 — Efficiency at TCASE = 100°C 4.8 5.6 6.4 7.2 8.0 360V 384V 400V 250 225 Ripple (mVPK-PK) 200 180 ROUT (mΩ) 4.0 Figure 9 — Power dissipation at TCASE = 100°C 220 160 140 120 200 175 150 125 100 75 50 25 100 80 3.2 Output Current (A) Output Current (A) VIN_DC: 2.4 0 -40 -20 0 20 40 60 80 100 0.0 0.8 BCM® Bus Converter Page 10 of 22 Rev 1.1 10/2016 3.2 VIN_DC: 7.05A Figure 10 — ROUT vs. temperature; nominal input 2.4 4.0 4.8 5.6 6.4 7.2 8.0 Output Current (A) Case Temperature (°C) IOUT_DC: 1.6 384V Figure 11 — Vripple vs. Iout: No external Cout, board mounted module, scope setting : 20MHz analog BW vicorpower.com 800 927.9474 BCM384x480y325Bzz Application Characteristics (Cont.) Figure 12 — Full load ripple, 2.2µF Cin: No external Cout, Board mounted module, scope setting : 20MHz analog BW Figure 13 — Start up from application of PC; Vin pre-applied Cout = 100µF, 100% IOUT R-load Figure 14 — 0A – 7.05A transient response: Cin = 2.2µF, Iin measured prior to Cin , no external Cout Figure 15 — 7.05A – 0A transient response: Cin = 2.2µF, Iin measured prior to Cin, no external Cout BCM® Bus Converter Page 11 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz General Characteristics Specifications apply over all line and load conditions, unless otherwise noted; boldface specifications apply over the temperature range of -40°C ≤ TCASE ≤ 100°C (T-Grade); All other specifications are at TCASE = 25ºC unless otherwise noted. Attribute Symbol Conditions / Notes Min Typ Max Unit Mechanical Length L 32.25 / [1.270] 32.50 / [1.280] 32.75 / [1.289] mm / [in] Width W 21.75 / [0.856] 22.00 / [0.866] 22.25 / [0.876] mm / [in] Height H 6.48 / [0.255] Volume Vol Weight W No heat sink Lead Finish 6.73 / [0.265] 6.98 / [0.275] mm / [in] 4.81 / [0.294] cm3/ [in3] 14.5 / [0.512] g / [oz] Nickel 0.51 2.03 Palladium 0.02 0.15 Gold 0.003 0.051 BCM384x480T325B00 (T-Grade) -40 125 BCM384x480M325B00 (M-Grade) -55 125 µm Thermal Operating temperature TJ Thermal resistance fJC Isothermal heatsink and isothermal internal PCB Thermal capacity °C 1 °C/W 9 Ws/°C Assembly Peak compressive force applied to case (Z-axis) Storage Temperature Supported by J-lead only TST lbs 5.41 lbs/ in2 BCM384x480T325B00 (T-Grade) -40 125 °C BCM384x480M325B00 (M-Grade) -55 125 °C ESDHBM Human Body Model, “JEDEC JESD 22-A114C.01”Class 1C 2000 ESDCDM Charge Device Model, “JEDEC JESD 22-C101-D” 500 ESD Withstand 6 V Soldering Peak temperature during reflow 245 °C Peak time above 217°C MSL 4 (Datecode 1528 and later) 60 90 s Peak heating rate during reflow 1.5 3 °C/s Peak cooling rate post reflow 1.5 6 °C/s 500 VDC Safety Working voltage (IN – OUT) VIN_OUT Isolation voltage (hipot) VHIPOT Isolation capacitance CIN_OUT Unpowered unit 500 Isolation resistance RIN_OUT At 500VDC 10 MTBF 4242 VDC 660 MIL-HDBK-217Plus Parts Count - 25°C Ground Benign, Stationary, Indoors / Computer Profile 3.2 MHrs Telcordia Issue 2 - Method I Case III; 25°C Ground Benign, Controlled 7.2 MHrs cURus CE Marked for Low Voltage Directive and ROHS recast directive, as applicable. BCM® Bus Converter Page 12 of 22 pF MΩ cTUVus Agency approvals / standards 800 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz Using the Control Signals PC, TM Primary Control (PC) pin can be used to accomplish the following functions: n Logic enable and disable for module: Once TON1 time has been satisfied, a PC voltage greater than VPC_EN will cause the module to start. Bringing PC lower than VPC_DIS will cause the module to enter standby. n Auxiliary voltage source: Once enabled in regular operational conditions (no fault), each BCM module PC provides a regulated 5V, 3.5mA voltage source. n Synchronized start up: In an array of parallel modules, PC pins should be connected to synchronize start up across units. This permits the maximum load and capacitance to scale by the number of paralleled modules. n Output disable: PC pin can be actively pulled down in order to disable the module. Pull down impedance shall be lower than 60Ω. n Fault detection flag: The PC 5V voltage source is internally turned off as soon as a fault is detected. n Note that PC can not sink significant current during a fault condition. The PC pin of a faulted module will not cause interconnected PC pins of other modules to be disabled. Temperature Monitor (TM) pin provides a voltage proportional to the absolute temperature of the converter control IC. It can be used to accomplish the following functions: n Monitor the control IC temperature: The temperature in Kelvin is equal to the voltage on the TM pin scaled by 100. (i.e. 3.0V = 300K = 27ºC). If a heat sink is applied, TM can be used to protect the system thermally. n Fault detection flag: The TM voltage source is internally turned off as soon as a fault is detected. For system monitoring purposes microcontroller interface faults are detected on falling edges of TM signal. BCM® Bus Converter Page 13 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz Sine Amplitude Converter™ Point of Load Conversion 1.94nH + VinIN V Rout 125mΩ ROUT out IIOUT Lin = 5.6nH RRcCin IN 9.2mΩ CIN C IN 0.1µF IIQQ 20.0mA + + – – K RRC cout OUT 110mΩ V•I 1/8 • Iout Lout = 600pH + 550µΩ 1/8 • Vin CCOUT out VVOUT out 5.6µF – – Figure 17 — VI Chip® module AC model The Sine Amplitude Converter (SAC™) uses a high frequency resonant tank to move energy from input to output. The resonant LC tank, operated at high frequency, is amplitude modulated as a function of input voltage and output current. A small amount of capacitance embedded in the input and output stages of the module is sufficient for full functionality and is key to achieving power density. The BCM384x480y325Bzz SAC can be simplified into the preceeding model. ROUT represents the impedance of the SAC, and is a function of the RDSON of the input and output MOSFETs and the winding resistance of the power transformer. IQ represents the quiescent current of the SAC control, gate drive circuitry, and core losses. The use of DC voltage transformation provides additional interesting attributes. Assuming that ROUT = 0Ω and IQ = 0A, Eq. (3) now becomes Eq. (1) and is essentially load independent, resistor R is now placed in series with VIN. At no load: R VOUT = VIN • K (1) VVin in + – SAC™ SAC 1/8 KK==1/32 Vout V out K represents the “turns ratio” of the SAC. Rearranging Eq (1): VOUT (2) K= VIN Figure 18 — K = 1/8 Sine Amplitude Converter with series input resistor The relationship between VIN and VOUT becomes: In the presence of load, VOUT is represented by: VOUT = (VIN – IIN • R) • K VOUT = VIN • K – IOUT • ROUT (3) and IOUT is represented by: IIN – IQ IOUT = K BCM® Bus Converter Page 14 of 22 (4) Rev 1.1 10/2016 (5) Substituting the simplified version of Eq. (4) (IQ is assumed = 0A) into Eq. (5) yields: VOUT = VIN • K – IOUT • R • K2 vicorpower.com 800 927.9474 (6) BCM384x480y325Bzz This is similar in form to Eq. (3), where ROUT is used to represent the characteristic impedance of the SAC™. However, in this case a real R on the input side of the SAC is effectively scaled by K 2 with respect to the output. Assuming that R = 1Ω, the effective R as seen from the secondary side is 15.6mΩ, with K = 1/8. A similar exercise should be performed with the additon of a capacitor or shunt impedance at the input to the SAC. A switch in series with VIN is added to the circuit. This is depicted in Figure 19. S VVin in + – C SAC™ SAC K = 1/8 K = 1/32 VVout out Low impedance is a key requirement for powering a highcurrent, low-voltage load efficiently. A switching regulation stage should have minimal impedance while simultaneously providing appropriate filtering for any switched current. The use of a SAC between the regulation stage and the point of load provides a dual benefit of scaling down series impedance leading back to the source and scaling up shunt capacitance or energy storage as a function of its K factor squared. However, the benefits are not useful if the series impedance of the SAC is too high. The impedance of the SAC must be low, i.e. well beyond the crossover frequency of the system. A solution for keeping the impedance of the SAC low involves switching at a high frequency. This enables small magnetic components because magnetizing currents remain low. Small magnetics mean small path lengths for turns. Use of low loss core material at high frequencies also reduces core losses. The two main terms of power loss in the BCM module are: n No load power dissipation (PNL): defined as the power used to power up the module with an enabled powertrain at no load. Figure 19 — Sine Amplitude Converter™ with input capacitor A change in VIN with the switch closed would result in a change in capacitor current according to the following equation: n Resistive loss (PR ): refers to the power loss across OUT the BCM module modeled as pure resistive impedance. PDISSIPATED = PNL + PROUT (10) Therefore, IC(t) = C dVIN (7) dt Assume that with the capacitor charged to VIN, the switch is opened and the capacitor is discharged through the idealized SAC. In this case, IC = IOUT • K (8) substituting Eq. (1) and (8) into Eq. (7) reveals: POUT = PIN – PDISSIPATED = PIN – PNL – PROUT The above relations can be combined to calculate the overall module efficiency: POUT PIN – PNL – PROUT h = = P P IN IN = VIN • IIN – PNL – (IOUT)2 • ROUT VIN • IIN IOUT = C • dVOUT K2 dt (9) = 1 – (PNL + (IOUT)2 • ROUT) VIN • IIN The equation in terms of the output has yielded a K 2 scaling factor for C, specified in the denominator of the equation. A K factor less than unity results in an effectively larger capacitance on the output when expressed in terms of the input. With a K = 1/8 as shown in Figure 19, C = 1µF would appear as C = 64µF when viewed from the output. BCM® Bus Converter Page 15 of 22 Rev 1.1 10/2016 (11) vicorpower.com 800 927.9474 (12) BCM384x480y325Bzz Input and Output Filter Design A major advantage of SAC™ systems versus conventional PWM converters is that the transformers do not require large functional filters. The resonant LC tank, operated at extreme high frequency, is amplitude modulated as a function of input voltage and output current and efficiently transfers charge through the isolation transformer. A small amount of capacitance embedded in the input and output stages of the module is sufficient for full functionality and is key to achieve power density. This paradigm shift requires system design to carefully evaluate external filters in order to: 1. Guarantee low source impedance: Within this frequency range, capacitance at the input appears as effective capacitance on the output per the relationship defined in Eq. 13. COUT = CIN K2 This enables a reduction in the size and number of capacitors used in a typical system. Thermal Considerations To take full advantage of the BCM module’s dynamic response, the impedance presented to its input terminals must be low from DC to approximately 5MHz. The connection of the bus converter module to its power source should be implemented with minimal distribution inductance. If the interconnect inductance exceeds 100nH, the input should be bypassed with a RC damper to retain low source impedance and stable operation. With an interconnect inductance of 200nH, the RC damper may be as high as 1µF in series with 0.3Ω. A single electrolytic or equivalent low-Q capacitor may be used in place of the series RC bypass. 2. Further reduce input and/or output voltage ripple without sacrificing dynamic response: Given the wide bandwidth of the module, the source response is generally the limiting factor in the overall system response. Anomalies in the response of the source will appear at the output of the module multiplied by its K factor. This is illustrated in Figures 15 and 16. VI Chip® products are multi-chip modules whose temperature distribution varies greatly for each part number as well as with the input / output conditions, thermal management and environmental conditions. Maintaining the top of the BCM384x480y325Bzz case to less than 100ºC will keep all junctions within the VI Chip module below 125ºC for most applications. The percent of total heat dissipated through the top surface versus through the J-lead is entirely dependent on the particular mechanical and thermal environment. The heat dissipated through the top surface is typically 60%. The heat dissipated through the J-lead onto the PCB surface is typically 40%. Use 100% top surface dissipation when designing for a conservative cooling solution. It is not recommended to use a VI Chip module for an extended period of time at full load without proper heat sinking. 3. Protect the module from overvoltage transients imposed by the system that would exceed maximum ratings and cause failures: The module input/output voltage ranges shall not be exceeded. An internal overvoltage lockout function prevents operation outside of the normal operating input range. Even during this condition, the powertrain is exposed to the applied voltage and power MOSFETs must withstand it. A criterion for protection is the maximum amount of energy that the input or output switches can tolerate if avalanched. Total load capacitance at the output of the BCM module shall not exceed the specified maximum. Owing to the wide bandwidth and low output impedance of the module, low-frequency bypass capacitance and significant energy storage may be more densely and efficiently provided by adding capacitance at the input of the module. At frequencies <500kHz the module appears as an impedance of ROUT between the source and load. BCM® Bus Converter Page 16 of 22 (13) Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz Current Sharing Fuse Selection The performance of the SAC™ topology is based on efficient transfer of energy through a transformer without the need of closed loop control. For this reason, the transfer characteristic can be approximated by an ideal transformer with a positive temperature coefficient series resistance. In order to provide flexibility in configuring power systems VI Chip® modules are not internally fused. Input line fusing of VI Chip products is recommended at system level to provide thermal protection in case of catastrophic failure. This type of characteristic is close to the impedance characteristic of a DC power distribution system both in dynamic (AC) behavior and for steady state (DC) operation. When multiple BCM modules of a given part number are connected in an array they will inherently share the load current according to the equivalent impedance divider that the system implements from the power source to the point of load. Some general recommendations to achieve matched array impedances include: n Dedicate common copper planes within the PCB The fuse shall be selected by closely matching system requirements with the following characteristics: n Current rating (usually greater than maximum current of BCM module) n Maximum voltage rating (usually greater than the maximum possible input voltage) n Ambient temperature n Nominal melting I2t n Recommend fuse: ≤ 2.5A Bussmann PC–Tron Fuse or ≤ 3.15A SOC type 36CFA Fuse. to deliver and return the current to the modules. n Provide as symmetric a PCB layout as possible among modules Reverse Operation n Apply same input / output filters (if present) to each unit. BCM modules are capable of reverse power operation. Once the unit is started, energy will be transferred from secondary back to the primary whenever the secondary voltage exceeds VIN • K. The module will continue operation in this fashion for as long as no faults occur. For further details see AN:016 Using BCM Bus Converters in High Power Arrays. VIN ZIN_EQ1 BCM®1 ZOUT_EQ1 R0_1 ZIN_EQ2 BCM®2 The BCM384x480y325Bzz has not been qualified for continuous operation in a reverse power condition. However, fault protections which help to protect the module in forward operation will also protect the module in reverse operation. VOUT ZOUT_EQ2 R0_2 + DC Load ZIN_EQn BCM®n Transient operation in reverse is expected in cases where there is significant energy storage on the output and transient voltages appear on the input. Transient reverse power operation of less than 1ms, 10% duty cycle is permitted and has been qualified to cover these cases. ZOUT_EQn R0_n Figure 20 — BCM module array BCM® Bus Converter Page 17 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz J-Lead Package Mechanical Drawing mm (inch) NOTES: mm 1. DIMENSIONS ARE inch . 2. UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE: .X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005] NOTES: mm 3. 1.PRODUCT MARKING DIMENSIONS ARE ON . SURFACE inchTOP 2. UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE: DXF.X and PDF files are available on/ vicorpower.com / [.XX] = +/-0.25 / [.01]; .XX [.XXX] = +/-0.13 / [.005] 3. PRODUCT MARKING ON TOP SURFACE DXF and PDF files are available on vicorpower.com J-Lead Package Recommended Land Pattern NOTES: mm 1. DIMENSIONS ARE inch . 2. UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE: .X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005] NOTES: mm 3. 1.PRODUCT MARKING DIMENSIONS ARE ON . SURFACE inchTOP 2. UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE: DXF.X and PDF=files are available on/ vicorpower.com / [.XX] +/-0.25 / [.01]; .XX [.XXX] = +/-0.13 / [.005] 3. PRODUCT MARKING ON TOP SURFACE DXF and PDF files are available on vicorpower.com BCM® Bus Converter Page 18 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz Through Hole Package Mechanical Drawing mm (inch) TOP VIEW ( COMPONENT SIDE ) TOP VIEW ( COMPONENT SIDE ) NOTES: NOTES: (mm) 1. DIMENSIONS ARE inch . (mm) 1. DIMENSIONS ARE inch . 2. UNLESS OTHERWISE SPECIFIED TOLERANCES ARE: X.X [X.XX] = ±0.25 [0.01]; X.XX [X.XXX] = ±0.13 2. UNLESS OTHERWISE SPECIFIED TOLERANCES ARE:[0.005] X.X [X.XX] = ±0.25 [0.01]; X.XX = ±0.13 [0.005] 3. RoHS COMPLIANT PER[X.XXX] CST-0001 LATEST REVISION 3. RoHS COMPLIANT PER CST-0001 LATEST REVISION DXF and PDF files are available on vicorpower.com DXF and PDF files are available on vicorpower.com Through Hole Package Recommended Land Pattern NOTES: NOTES: (mm) 1. DIMENSIONS ARE inch . (mm) 1. DIMENSIONS ARE . inch 2. UNLESS OTHERWISE SPECIFIED TOLERANCES ARE: X.X [X.XX] = ±0.25 [0.01]; X.XX [X.XXX] = ±0.13 2. UNLESS OTHERWISE SPECIFIED TOLERANCES ARE:[0.005] X.X [X.XX] = ±0.25 [0.01]; X.XX = ±0.13 [0.005] 3. RoHS COMPLIANT PER[X.XXX] CST-0001 LATEST REVISION RECOMMENDED HOLE PATTERN RECOMMENDED HOLESIDE PATTERN ( COMPONENT SHOWN ) ( COMPONENT SIDE SHOWN ) 3. RoHS COMPLIANT PER CST-0001 LATEST REVISION DXF and PDF files are available on vicorpower.com DXF and PDF files are available on vicorpower.com BCM® Bus Converter Page 19 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474 BOTTOM VIEW BOTTOM VIEW BCM384x480y325Bzz Recommended Heat Sink Push Pin Location (NO GROUNDING CLIPS) (WITH GROUNDING CLIPS) Notes: 1. Maintain 3.50 (0.138) Dia. keep-out zone free of copper, all PCB layers. 2. (A) Minimum recommended pitch is 39.50 (1.555). This provides 7.00 (0.275) component edge-to-edge spacing, and 0.50 (0.020) clearance between Vicor heat sinks. (B) Minimum recommended pitch is 41.00 (1.614). This provides 8.50 (0.334) component edge-to-edge spacing, and 2.00 (0.079) clearance between Vicor heat sinks. BCM® Bus Converter Page 20 of 22 3. VI Chip® module land pattern shown for reference only; actual land pattern may differ. Dimensions from edges of land pattern to push–pin holes will be the same for all full-size VI Chip® products. 5. Unless otherwise specified: Dimensions are mm (inches) tolerances are: x.x (x.xx) = ±0.3 (0.01) x.xx (x.xxx) = ±0.13 (0.005) 4. RoHS compliant per CST–0001 latest revision. 6. Plated through holes for grounding clips (33855) shown for reference, heat sink orientation and device pitch will dictate final grounding solution. Rev 1.1 10/2016 vicorpower.com 800 927.9474 BCM384x480y325Bzz Revision History Revision Date 1.0 09/30/16 Initial release n/a 1.1 10/12/16 Specification corrections 5, 7 BCM® Bus Converter Page 21 of 22 Description Rev 1.1 10/2016 vicorpower.com 800 927.9474 Page Number(s) BCM384x480y325Bzz 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. Vicor disclaims any and all liability arising out of the application or use of any product or circuit and assumes no liability for applications assistance or buyer product design. Buyers are responsible for their products and applications using Vicor products and components. Prior to using or distributing any products that include Vicor components, buyers should provide adequate design, testing and operating safeguards. Vicor will repair or replace defective products in accordance with its own best judgment. For service under this warranty, the buyer must contact Vicor to obtain a Return Material Authorization (RMA) number and shipping instructions. Products returned without prior authorization will be returned to the buyer. The buyer will pay all charges incurred in returning the product to the factory. Vicor will pay all reshipment charges if the product was defective within the terms of this warranty. 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: 5,945,130; 6,403,009; 6,710,257; 6,911,848; 6,930,893; 6,934,166; 6,940,013; 6,969,909; 7,038,917; 7,145,186; 7,166,898; 7,187,263; 7,202,646; 7,361,844; D496,906; D505,114; D506,438; D509,472; and for use under 6,975,098 and 6,984,965. 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] BCM® Bus Converter Page 22 of 22 Rev 1.1 10/2016 vicorpower.com 800 927.9474