BCM® Bus Converter BCM48BH120T120B00 S C NRTL US Fixed Ratio DC-DC Converter FEATURES DESCRIPTION The VI Chip® Bus Converter is a high efficiency (>95%) Sine Amplitude ConverterTM (SACTM) operating from a 38 to 55 Vdc primary bus to deliver an isolated ratiometric output from 9.5 to 13.75. The SAC offers a low AC impedance beyond the bandwidth of most downstream regulators, meaning that input capacitance normally located at the input of a 12 V regulator can be located at the input to the SAC. Since the K factor of the BCM48BH120T120B00 is 1/4, that capacitance value can be reduced by a factor of 16x, resulting in savings of board area, materials and total system cost. • 48 Vdc – 12 Vdc 120 W Bus Converter • High efficiency (>95%) reduces system power consumption • High power density (801 W/in3) reduces power system footprint by >50% • “Half Chip” VI Chip® package enables surface mount, low impedance interconnect to system board • Contains built-in protection features against: - The BCM48BH120T120B00 is provided in a VI Chip package compatible with standard pick-and-place and surface mount assembly processes. The VI Chip package provides flexible thermal management through its low junction-to-case and junction-to-board thermal resistance. With high conversion efficiency the BCM48BH120T120B00 increases overall system efficiency and lowers operating costs compared to conventional approaches. Undervoltage Overvoltage Overcurrent Short Circuit Overtemperature • Provides enable/disable control, internal temperature monitoring • ZVS/ZCS Resonant Sine Amplitude Converter topology • Less than 50°C temperature rise at full load in typical applications TYPICAL APPLICATION • High End Computing Systems • Automated Test Equipment • Telecom Base Stations • High Density Power Supplies • Communication Systems VIN = 38 – 55 V POUT = 120 W(NOM) VOUT = 9.5 – 13.75 V (NO LOAD) K = 1/4 PART NUMBERING PART NUMBER BCM48BH120 x 120 B00 PRODUCT GRADE T = -40° to 125°C M = -55° to 125°C For Storage and Operating Temperatures see Section 6.0 General Characteristics TYPICAL APPLICATION POL enable / disable switch TM PC SW1 F1 VIN 3.15 A POL BCM® BCM™ +In C1 POL +Out 10 µF VOUT -In -Out BCM® Bus Converter Rev 1.2 vicorpower.com Page 1 of 16 07/2015 800 927.9474 POL BCM48BH120T120B00 ABSOLUTE MAXIMUM RATINGS CONTROL PIN SPECIFICATIONS +IN to –IN . . . . . . . . . . . . . . . . . . . . . . . . . -1.0 Vdc – +60 Vdc PC to –IN . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 Vdc – +20 Vdc TM to –IN . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 Vdc – +7.0 Vdc +IN/-IN to +OUT/-OUT . . . . . . . . . . . . . . . . . . . 2250 V (Hi Pot) +IN/-IN to +OUT/-OUT . . . . . . . . . . . . . . . . . . . . 60 V (working) +OUT to –OUT . . . . . . . . . . . . . . . . . . . . . . -1.0 Vdc - +16 Vdc Temperature during reflow . . . . . . . . . . . . . . . . 245°C (MSL 4) See section 5.0 for further application details and guidelines. PACKAGE ORDERING INFORMATION 4 3 2 1 A +Out +In B C D E F G H J K -Out L M NC TM NC PC -In Bottom View Signal Name +In –In NC TM NC PC +Out –Out PC (BCM® Primary Control) The PC pin can enable and disable the BCM module. When held below VPC-DIS the BCM shall be disabled. When allowed to float with an impedance to –IN of greater than 60 kΩ the module will start. When connected to another BCM PC pin (either directly, or isolated through a diode), the BCM modules will start simultaneously when enabled. The PC pin is capable of being either driven high by an external logic signal or internal pull up to 5 V (operating). TM (BCM® Temperature Monitor) The TM pin monitors the internal temperature of the BCM module within an accuracy of +5/-5 °C. It has a room temperature setpoint of ~3.0 V and an approximate gain of 10 mV/°C. It can source up to 100 uA and may also be used as a “Power Good” flag to verify that the BCM module is operating. Designation A1-B1, A2-B2 L1-M1, L2-M2 E1 F2 G1 H2 A3-D3, A4-D4 J3-M3, J4-M4 BCM® Bus Converter Rev 1.2 vicorpower.com Page 2 of 16 07/2015 800 927.9474 BCM48BH120T120B00 1.0 ELECTRICAL CHARACTERISTICS Specifications apply over all line and load conditions unless otherwise noted; Boldface specifications apply over the temperature range of -40°C < TJ < 125°C (T-Grade); All other specifications are at TJ = 25º unless otherwise noted ATTRIBUTE Voltage range dV/dt Quiescent power No load power dissipation SYMBOL VIN dVIN /dt PQ PNL Inrush current peak IINR-P DC input current IIN-DC K factor ( ) VOUT VIN Output power (average) CONDITIONS / NOTES MIN TYP MAX UNIT 38 48 55 1 150 4.1 5 Vdc V/µs mW 12 A 3.5 A VIN = 38 – 55 Vdc; See Figure 14 VIN = 46 – 55 Vdc; See Figure 14 97 120 W VIN = 46 – 55 Vdc Average POUT < = 120 W, Tpeak < 10 ms 150 W 14 10.0 V A PC connected to -IN VIN = 48 V VIN = 38 to 55 V VIN = 48 V COUT = 500 µF, IOUT = 10.55 A 68 2.1 5.5 K POUT Output power (peak) POUT-P Output voltage Output current (average) VOUT IOUT 1/4 Efficiency (ambient) h Efficiency (hot) Minimum efficiency (over load range) Output resistance (ambient) Output resistance (hot) Output resistance (cold) Load capacitance Switching frequency Ripple frequency h Section 3.0 Pout < =120 W VIN = 48 V, POUT = 120 W VIN = 38 V to 55 V, POUT = 100 W VIN = 48 V, TJ = 100°C, POUT = 120 W h 24 W < POUT < POUT Max ROUT ROUT ROUT COUT FSW FSW-RP Output voltage ripple VOUT-PP VIN to VOUT (application of VIN) TON1 PC PC voltage (operating) PC voltage (enable) PC voltage (disable) PC source current (start up) PC source current (operating) PC internal resistance PC capacitance (internal) PC capacitance (external) External PC resistance PC external toggle rate PC to VOUT with PC released PC to VOUT, disable PC VPC VPC-EN VPC-DIS IPC-EN IPC-OP RPC-SNK CPC_INT CPC_EXT RPC FPC-TOG Ton2 TPC-DIS W TJ = 25°C TJ = 125°C TJ = -40°C 8.5 93.5 92 92.6 VIN = 48 V, Pre-applied; See Figure 16 VIN = 48 V, Pre-applied; See Figure 16 BCM® Bus Converter Rev 1.2 vicorpower.com Page 3 of 16 07/2015 800 927.9474 % 93.5 % 72 % 25.0 30 20 38.8 47.3 28.7 1.5 3.0 50.0 60 40 500 1.6 3.2 mΩ mΩ mΩ uF MHz MHz 1.4 2.8 200 400 mV 570 800 ms 4.7 2.0 5.0 2.5 50 100 50 150 5.3 3.0 1.95 300 2 400 588 1000 V V V uA mA kΩ pF pF kΩ Hz µs µs COUT = 0 µF, IOUT = 10.55 A, VIN = 48 V, Section 8.0 VIN = 48 V, CPC = 0; See Figure 16 Internal pull down resistor Section 5.0 External capacitance delays PC enable time Connected to –VIN 94.6 60 60 4 1 100 10 BCM48BH120T120B00 1.0 ELECTRICAL CHARACTERISTICS (CONT.) Specifications apply over all line and load conditions unless otherwise noted; Boldface specifications apply over the temperature range of -40°C < TJ < 125°C (T-Grade); All other specifications are at TJ = 25º unless otherwise noted ATTRIBUTE TM TM accuracy TM gain TM source current TM internal resistance External TM capacitance TM voltage ripple PROTECTION Negative going OVLO Positive going OVLO Negative going UVLO Positive going UVLO Output overcurrent trip Short circuit protection trip current Short circuit protection response time Thermal shutdown junction setpoint GENERAL SPECIFICATION Isolation voltage (Hi-Pot) Working voltage (IN – OUT) Isolation vapacitance Isolation resistance MTBF SYMBOL Actm ATM ITM RTM-SNK CTM VTM-PP VIN OVLOVIN OVLO+ VIN UVLOVIN UVLO+ IOCP CONDITIONS / NOTES MIN TYP -5 MAX UNIT +5 ºC mV/°C uA kΩ pF mV 10 CTM = 0 uF, VIN = 55 V, POUT = 120 W VIN = 48 V, 25°C 25 40 75 180 100 50 50 250 55.1 55.5 29.1 30.7 12 58.7 58.1 31.5 32.9 17 60 60 35.4 37.3 24 V V V V A 40 A ISSP 24 TSSP 0.8 1.0 1.2 us TJ-OTP 125 130 135 °C VHIPOT VWORKING CIN-OUT RIN-OUT 2250 1750 60 2150 Unpowered unit 1350 10 MIL HDBK 217F, 25°C, GB cTUVus CE Mark Agency approvals / standards 7.1 CE Marked for Low Voltage Directive and ROHS recast directive, as applicable BCM® Bus Converter Rev 1.2 vicorpower.com Page 4 of 16 07/2015 800 927.9474 V V pF MΩ Mhrs BCM48BH120T120B00 1.1 APPLICATION CHARACTERISTICS All specifications are at TJ = 25ºC unless otherwise noted. See associated figures for general trend data. ATTRIBUTE SYMBOL No load power Inrush current peak PNL INR-P Efficiency (ambient) η Efficiency (hot – 100°C) η Output resistance (-40°C) Output resistance (25°C) Output resistance (100°C) ROUT_C ROUT_R ROUT_H Output voltage ripple VOUT-PP VOUT transient (positive) VOUT-TRAN+ VOUT transient (negative) VOUT-TRAN- Undervoltage lockout response time Output overcurrent response time Overvoltage lockout response time CONDITIONS / NOTES TYP UNIT VIN = 48 V, PC enabled; See Figure 1 COUT = 500 µF, POUT = 120 W VIN = 48 V, POUT = 120 W COUT = 500 µF VIN = 48 V, POUT = 120 W COUT = 500 µF VIN = 48 V VIN = 48 V VIN= 48 V COUT = 0uF, POUT = 120 W @ VIN = 48, VIN = 48 V IOUT_STEP = 0 TO 10.55 A, ISLEW >10 A/us; See Figure 12 IOUT_STEP = 10.55 A to 0 A, ISLEW > 10 A/us; See Figure 11 1.75 6 W A 95 % 94 % 35 44 56 mΩ mΩ mΩ 160 mV 1.4 V 1.3 V 2.4 us 4.4 ms 2.4 µs TUVLO TOCP 12 < IOCP < 25 A TOVLO BCM® Bus Converter Rev 1.2 vicorpower.com Page 5 of 16 07/2015 800 927.9474 BCM48BH120T120B00 Full Load Efficiency vs. Case Temperature 96 95 2.5 Efficiency (%) 2 1.5 94 93 92 91 1 -40 38 40 42 44 46 47 49 51 53 -20 55 -40ºC 25ºC 96 94 14 94 92 12 10 90 8 PD 6 4 84 82 2 80 0 38 V VIN : 4 6 8 Output Load (A) 48 V 55 V 10 η 88 8 86 38 V 48 V 55 V 84 4 82 2 0 2 38 V VIN: 55 86 6 PD 4 82 2 80 0 48 V 48 V 55 V 10 12 8 10 55 V 38 V 12 48 V 55 V 40 35 30 25 20 -40 -20 0 20 40 Temperature (°C) 38 V 48 V 45 Output Load (A) 38 V 8 50 ROUT (mW) 8 Power Dissipation (W) Efficiency (%) 14 88 VIN : 6 ROUT vs. TCASE at VIN = 48 V 60 12 6 4 Figure 4 — Efficiency and power dissipation at 25°C (case); VIN 16 10 4 6 PD 0 90 2 12 Output Load (A) η 0 14 10 Efficiency & Power Dissipation 100°C Case 84 55 V 90 12 96 92 48 V 80 Figure 3 — Efficiency and power dissipation at -40°C (case); VIN 94 100 16 92 Efficiency (%) Efficiency (%) Power Dissipation (W) 16 2 80 Efficiency & Power Dissipation 25°C Case Efficiency & Power Dissipation -40°C Case 0 60 Figure 2 — Full load efficiency vs. temperature; VIN 96 86 40 38 V VIN : 100ºC Figure 1 — No load power dissipation vs. VIN ; TCASE 88 20 Case Temperature (C) Input Voltage (V) TCASE: 0 Power Dissipation (W) No Load Power Dissipation (W) No Load Power Dissipation vs. Line 3 55 V Figure 5 — Efficiency and power dissipation at 100°C (case); VIN I OUT : 10.0 A Figure 6 — ROUT vs. temperature vs. IOUT BCM® Bus Converter Rev 1.2 vicorpower.com Page 6 of 16 07/2015 800 927.9474 60 80 100 BCM48BH120T120B00 Output Voltage Ripple vs. Load Ripple (mV pk-pk) 200 175 150 125 100 75 50 0 1 2 3 4 5 6 7 8 9 10 Load Current (A) VIN: 48 V Figure 7 — Vripple vs. IOUT ; 48 VIN , no external capacitance Figure 8 — PC to VOUT start up waveform Figure 9 — VIN to VOUT start up waveform Figure 10 — Output voltage and input current ripple, 48 VIN ,120 W no COUT Figure 11 — Positive load transient (0 – 11.3 A) Figure 12 — Negative load transient (11.3 A – 0 A) BCM® Bus Converter Rev 1.2 vicorpower.com Page 7 of 16 07/2015 800 927.9474 BCM48BH120T120B00 POUT (W) q 120 q 97 38 Figure 13 — PC disable waveform, 48 VIN , 500 µF COUT full load 48 VIN (VDC) 55 Figure 14 — POUT derating vs. VIN 2.0 PACKAGE/MECHANICAL SPECIFICATIONS All specifications are at TJ = 25ºC unless otherwise noted. See associated figures for general trend data. ATTRIBUTE SYMBOL CONDITIONS / NOTES Length Width Height Volume Footprint L W H Vol F No heat sink No heat sink Power density PD No heat sink Weight W ESD rating Peak temperature during reflow Peak time above 217°C Peak heating rate during reflow Peak cooling rate post reflow [a] [b] TYP MAX UNIT 21.7 / 0.854 22.0 / 0.866 22.3 / 0.878 mm/in 16.37 / 0.644 16.50 / 0.650 16.63 / 0.655 mm/in 6.48 / 0.255 6.73 / 0.265 6.98 / 0.275 mm/in 2.44 / 0.150 cm3/in3 3.6 / 0.56 cm2/in2 801 W/in3 W/cm3 49 0.28/8 oz/g Nickel (0.51-2.03 µm) Palladium (0.02-0.15 µm) Gold (0.003-0.05 µm) Lead finish Operating temperature Storage temperature Thermal impedance Thermal capacity Peak compressive force Applied to case (Z-axis) MIN TJ TST ØJC -40 -40 Junction to case 125 125 2.7 °C °C °C/W Ws/°C 3.0 lbs 245 150 3 6 VDC VDC °C s °C/s °C/s 5 Supported by J-leads only ESDHBM ESDMM Human Body Model[a] Machine Model[b] MSL 4 (Datecode 1528 and later) 2.5 1500 400 1.5 1.5 JEDEC JESD 22-A114C.01 JEDED JESD 22-A115-A BCM® Bus Converter Rev 1.2 vicorpower.com Page 8 of 16 07/2015 800 927.9474 BCM48BH120T120B00 2.1 MECHANICAL DRAWING BOTTOM VIEW TOP VIEW ( COMPONENT SIDE ) mm (inch) NOTES: mm 2. DIMENSIONS ARE inch . UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE: 3. .X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005] 4. PRODUCT MARKING ON TOP SURFACE DXF and PDF files are available on vicorpower.com 2.2 RECOMMENDED LAND PATTERN 4 RECOMMENDED LAND PATTERN 3 2 1 A +Out ( COMPONENT SIDE SH OWN ) +In B C D E F G H J K -Out L M Bottom View NOTES: 3. .X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005] mm 2. DIMENSIONS ARE inch . UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE: 4. PRODUCT MARKING ON TOP SURFACE DXF and PDF files are available on vicorpower.com Signal Name +In –In NC TM NC PC +Out –Out Designation A1-B1, A2-B2 L1-M1, L2-M2 E1 F2 G1 H2 A3-D3, A4-D4 J3-M3, J4-M4 2.3 RECOMMENDED LAND PATTERN FOR PUSH PIN HEAT SINK Notes: 1. Maintain 3.50 (0.138) Dia. keep-out zone free of copper, all PCB layers. 2. (A) minimum recommended pitch is 24.00 (0.945) this provides 7.50 (0.295) component edge–to–edge spacing, and 0.50 (0.020) clearance between Vicor heat sinks. (B) Minimum recommended pitch is 25.50 (1.004). This provides 9.00 (0.354) component edge–to–edge spacing, and 2.00 (0.079) clearance between Vicor heat sinks. 3. V•I 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 half size V•I Chip products. 4. RoHS compliant per CST–0001 latest revision. 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) 6. Plated through holes for grounding clips (33855) shown for reference. Heat sink orientation and device pitch will dictate final grounding solution. (NO GROUNDING CLIPS) BCM® Bus Converter Rev 1.2 vicorpower.com Page 9 of 16 07/2015 800 927.9474 (WITH GROUNDING CLIPS) NC TM NC PC -In BCM48BH120T120B00 3.0 POWER, VOLTAGE, EFFICIENCY RELATIONSHIPS Because of the high frequency, fully resonant SAC topology, power dissipation and overall conversion efficiency of BCM® converters can be estimated as shown below. OUTPUT POWER INPUT POWER Key relationships to be considered are the following: 1. Transfer Function P R OUT a. No load condition P NL VOUT = VIN • K Eq. 1 Figure 15 — Power transfer diagram Where K (transformer turns ratio) is constant for each part number b. Loaded condition VOUT = Vin • K – IOUT • ROUT Eq. 2 2. Dissipated Power The two main terms of power losses in the BCM module are: - No load power dissipation (PNL ) defined as the power used to power up the module with an enabled power train at no load. - Resistive loss (ROUT) refers to the power loss across the BCM module modeled as pure resistive impedance. ~ PNL + PR PDISSIPATED ~ OUT Eq. 3 Therefore, with reference to the diagram shown in Figure 15 POUT = PIN – PDISSIPATED = PIN – PNL – PROUT Eq. 4 Notice that ROUT is temperature and input voltage dependent and PNL is temperature dependent (See Figure 15). The above relations can be combined to calculate the overall module efficiency: h = POUT PIN = PIN – PNL – PROUT PIN = VIN • IIN – PNL – (IOUT)2 • ROUT VIN • IIN =1– BCM® Bus Converter Rev 1.2 vicorpower.com Page 10 of 16 07/2015 800 927.9474 ( PNL + (IOUT)2 • ROUT VIN • IIN ) Eq. 5 NL 5V 2.5 V 5V 3V PC VUVLO+ VUVLO– Figure 16 — Timing diagram BCM® Bus Converter Rev 1.2 vicorpower.com Page 11 of 16 07/2015 800 927.9474 1 A E: TON2 F: TOCP G: TPC–DIS H: TSSP** B D 1: Controller start 2: Controller turn off 3: PC release C *Min value switching off **From detection of error to power train shutdown A: TON1 B: TOVLO* C: Max recovery time 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 voltage is not to scale – Error pulse width is load dependent 6 BCM48BH120T120B00 4.0 OPERATING BCM48BH120T120B00 5.0 USING THE CONTROL SIGNALS TM AND PC The PC control pin can be used to accomplish the following functions: • Delayed start: At start up, PC pin will source a constant 100 uA current to the internal RC network. Adding an external capacitor will allow further delay in reaching the 2.5 V threshold for module start. • Synchronized start up: In a parallel module array, PC pins shall be connected in order to ensure synchronous start of all the units. While every controller has a calibrated 2.5 V reference on PC comparator, many factors might cause different timing in turning on the 100 uA current source on each module, i.e.: – Different VIN slew rate – Statistical component value distribution By connecting all PC pins, the charging transient will be shared and all the modules will be enabled synchronously. • Auxiliary voltage source: Once enabled in regular operational conditions (no fault), each BCM® module PC provides a regulated 5 V, 2 mA voltage source. • Output disable: PC pin can be actively pulled down in order to disable module operations. Pull down impedance shall be lower than 1 kΩ and toggle rate lower than 1 Hz. • Fault detection flag: The PC 5 V voltage source is internally turned off as soon as a fault is detected. After a minimum disable time, the module tries to re-start, and PC voltage is re-enabled. For system monitoring purposes (microcontroller interface) faults are detected on falling edges of PC signal. It is important to notice that PC doesn’t have current sink capability (only 150 kΩ typical pull down is present), therefore, in an array, PC line will not be capable of disabling all the modules if a fault occurs on one of them. 6.0 FUSE SELECTION VI Chip productss are not internally fused in order to provide flexibility in configuring power systems. Input line fusing of VI Chip modules 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: • Current rating (usually greater than maximum BCM converter current) • Maximum voltage rating (usually greater than the maximum possible input voltage) • Ambient temperature • Nominal melting I2t • Recommended fuse: 3.15 A Little Fuse Nano2 Fuse The 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: • Monitor the control IC temperature: The temperature in Kelvin is equal to the voltage on the TM pin scaled by x100. (i.e. 3.0 V = 300 K = 27ºC). It is important to remember that VI Chip® products are multi-chip modules, whose temperature distribution greatly vary for each part number as well with input/output conditions, thermal management and environmental conditions. Therefore, TM cannot be used to thermally protect the system. • Fault detection flag: The TM voltage source is internally turned off as soon as a fault is detected. After a minimum disable time, the module tries to re-start, and TM voltage is re-enabled. BCM® Bus Converter Rev 1.2 vicorpower.com Page 12 of 16 07/2015 800 927.9474 BCM48BH120T120B00 7.0 CURRENT SHARING The SAC™ topology bases its performance 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 some resistive drop and positive temperature coefficient. This type of characteristic is close to the impedance characteristic of a DC power distribution system, both in behavior (AC dynamic) and absolute value (DC dynamic). When connected in an array (with same K factor), the BCM® module will inherently share the load current with parallel units, according to the equivalent impedance divider that the system implements from the power source to the point of load. It is important to notice that, when successfully started, BCM converters are capable of bidirectional operations (reverse power transfer is enabled if the BCM converter input falls within its operating range and the BCM converter is otherwise enabled). In parallel arrays, because of the resistive behavior, circulating currents are never experienced, because of energy conservation law. General recommendations to achieve matched array impedances are (see also AN016 for further details): • to dedicate common copper planes within the PCB to deliver and return the current to the modules • to make the PCB layout as symmetric as possible • to apply same input/output filters (if present) to each unit Figure 17 — BCM® module array BCM® Bus Converter Rev 1.2 vicorpower.com Page 13 of 16 07/2015 800 927.9474 BCM48BH120T120B00 8.0 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: To take full advantage of the BCM® module dynamic response, the impedance presented to its input terminals must be low from DC to approximately 5 MHz. The connection of the module to its power source should be implemented with minimal distribution inductance. If the interconnect inductance exceeds 100 nH, the input should be bypassed with a RC damper to retain low source impedance and stable operation. With an interconnect inductance of 200 nH, the RC damper may be as high as 47 µF in series with 0.3 Ω. A single electrolytic or equivalent low-Q capacitor may be used in place of the series RC bypass. Total load capacitance at the output of the 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 <500 kHz the module appears as an impedance of ROUT between the source and load. Within this frequency range capacitance at the input appears as effective capacitance on the output per the relationship defined in Eq. 6. COUT = CIN K2 Eq. 6 This enables a reduction in the size and number of capacitors used in a typical system. 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 11 and 12. 3.Protect the module from overvoltage transients imposed by the system that would exceed maximum ratings and cause failures: The BCM 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. BCM® Bus Converter Rev 1.2 vicorpower.com Page 14 of 16 07/2015 800 927.9474 Figure 18 – BCM® module behavioral block diagram BCM® Bus Converter Rev 1.2 vicorpower.com Page 15 of 16 07/2015 800 927.9474 TM PC -Vin +Vin 560 pF 2.5 V 40 K 5V Voltage dependent temperature sensor 2.5 V One shot delay 320/540 ms 2 mA PC Pull-Up & Source 150 K 1.5 k 100 uA UVLO OVLO 18.5 V Wake-Up Power and Logic Vref (125°C) Primary Gate Drive supply Min. off time and restart Enable Modulator Vref Over-Current Protection Slow current limit Fast current limit Differential primary current sensing Primary Stage & Resonant Tank -Vout +Vout BCM48BH120T120B00 BCM48BH120T120B00 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. 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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; 7,166,898; 7,187,263; 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 Rev 1.2 vicorpower.com Page 16 of 16 07/2015 800 927.9474