DCM™ DC-DC Converter DCM3623x50M31C2y7z ® S US C C NRTL US Isolated, Regulated DC Converter Features & Benefits Product Ratings • Isolated, regulated DC-DC converter • Up to 320 W, 11.43 A continuous • 93.6% peak efficiency • 818 W/in3 Power density VIN = 16 V to 50 V POUT = 320 W VOUT = 28.0 V (22.0 V to 30.8 V Trim) IOUT = 11.43 A Product Description • Wide input range 16 – 50 Vdc The DCM Isolated, Regulated DC Converter is a DC-DC converter, operating from an unregulated, wide range input to generate an isolated 28.0 Vdc output. With its high frequency zero voltage switching (ZVS) topology, the DCM converter consistently delivers high efficiency across the input line range. Modular DCM converters and downstream DC-DC products support efficient power distribution, providing superior power system performance and connectivity from a variety of unregulated power sources to the point-of-load. • Safety Extra Low Voltage (SELV) 28.0 V Nominal Output • 2250 Vdc isolation • ZVS high frequency switching n Enables low-profile, high-density filtering • Fully operational current limit • OV, OC, UV, short circuit and thermal protection • 3623 through-hole ChiP package Leveraging the thermal and density benefits of Vicor’s ChiP packaging technology, the DCM module offers flexible thermal management options with very low top and bottom side thermal impedances. Thermally-adept ChiP based power components enable customers to achieve cost effective power system solutions with previously unattainable system size, weight and efficiency attributes, quickly and predictably. n 1.524” x 0.898” x 0.284” (38.72 mm x 22.8 mm x 7.21 mm) Typical Applications • • • • Industrial Process Control Heavy Equipment Defense / Aerospace Part Ordering Information Product Function Package Size Package Type Max Input Voltage Range Ratio Max Output Voltage Max Output Power Temperature Grade Option 50 M 31 C2 y 7z T = -40°C – 125°C 70 = Enhanced VOUT Regulation / Analog Control Interface Version DCM 36 23 x DCM = DC-DC Converter Length in mm x 10 Width in mm x 10 T= Through hole ChiPs Internal Reference DCM™ DC-DC Converter Rev 1.0 Page 1 of 23 08/2017 M = -55°C – 125°C DCM3623x50M31C2y7z Typical Application DCM TR EN L2 F1 Vin Load 1 FT R1 L1 +IN +OUT C1 COUT-EXT -IN -OUT Non-isolated Point-of-Load Regulator Load 2 Typical Application: Single DCM3623x50M31C2y7z, to a non-isolated regulator, and direct to load DCM™ DC-DC Converter Rev 1.0 Page 2 of 23 08/2017 DCM3623x50M31C2y7z Pin Configuration TOP VIEW 1 2 +IN A A’ +OUT TR B B’ -OUT EN C C’ +OUT FT D -IN E D’ -OUT 3623 ChiP Package Pin Descriptions Pin Number Signal Name Type A1 +IN INPUT POWER B1 TR INPUT Enables and disables trim functionality. Adjusts output voltage when trim active. C1 EN INPUT Enables and disables power supply D1 FT OUTPUT E1 -IN INPUT POWER RETURN Negative input power terminal A’2, C’2 +OUT OUTPUT POWER Positive output power terminal B’2, D’2 -OUT OUTPUT POWER RETURN Negative output power terminal Function Positive input power terminal Fault monitoring DCM™ DC-DC Converter Rev 1.0 Page 3 of 23 08/2017 DCM3623x50M31C2y7z 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. Electrical specifications do not apply when operating beyond rated operating conditions. Parameter Comments Input Voltage (+IN to –IN) Input Voltage Slew Rate Min Max Unit -0.5 65.0 V -1 1 V/µs TR to - IN -0.3 3.5 V EN to -IN -0.3 3.5 V -0.3 3.5 V 5 mA 39.2 V FT to -IN Output Voltage (+Out to –Out) Dielectric withstand (input to output) -0.5 Basic insulation 2250 Vdc T Grade -40 125 °C M Grade -55 125 °C T Grade -40 125 °C M Grade -65 125 °C 14.5 A Internal Operating Temperature Storage Temperature Average Output Current Figure 1 — Thermal Specified Operating Area: Max Output Power Figure 2 — Electrical Specified Operating Area vs. Case Temp, module at minimum full load efficiency DCM™ DC-DC Converter Rev 1.0 Page 4 of 23 08/2017 DCM3623x50M31C2y7z Electrical Specifications Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade. Attribute Symbol Conditions / Notes Min Typ Max Unit 16 28 50 V Power Input Specification Input voltage range Inrush current (peak) VIN Continuous operation IINRP With maximum COUT-EXT, full resistive load 30.0 A Input capacitance (internal) CIN-INT Effective value at nominal input voltage 29.7 µF Input capacitance (internal) ESR RCIN-INT At 1 MHz 0.73 mΩ Input inductance (external) LIN Differential mode, with no further line bypassing 1 µH 0.4 W 0.5 W 5.8 W 8.5 W No Load Specification Nominal line, see Fig. 3 Input power – disabled PQ 0.3 Worst case line, see Fig. 3 Nominal line, see Fig. 4 Input power – enabled with no load PNL 3.0 Worst case line, see Fig. 4 Power Output Specification Output voltage set point Rated output voltage trim range Output voltage light load regulation VOUT accuracy VOUT-NOM VOUT-TRIMMING ΔVOUT-LL %VOUT-ACCURACY Rated output power POUT Rated output current IOUT 27.86 28.0 28.14 V Trim range over temp, with > 5% rated load. Specifies the Low, Nominal and High Trim conditions. 22.0 28.0 30.8 V 0% to 5% load, additional VOUT relative to VOUT accuracy; see Fig. 5 and Sec. Design Guidelines -0.00 5.01 V The total output voltage setpoint accuracy from the calculated ideal VOUT based on trim. Excludes ΔVOUT-LL -1.0 1.0 % Continuous, VOUT ≥ 28.0 V Continuous, VOUT ≤ 28.0 V Output current limit IOUT-LM Of rated IOUT max. Fully operational current limit, for nominal trim and below Current limit delay tIOUT-LIM The module will power limit in a fast transient event Efficiency η 320 W 11.43 A 100 115 123 % 1 ms Full load, nominal line, nominal trim 92.9 93.6 % Full load, over line and temperature, nominal trim 91.4 % 50% load, over rated line, temperature and trim 90.0 % Output voltage ripple VOUT-PP 20 MHz bandwidth. At nominal trim, minimum COUT-EXT and at least 5 % rated load 535 mV Output capacitance (internal) COUT-INT Effective value at nominal output voltage 33 µF Output capacitance (internal) ESR RCOUT-INT At 1 MHz 0.069 mΩ TRANS-TRIM Excludes component temperature coefficient For load transients that remain > 5% rated load Excludes component temperature coefficient For load transients down to 0% rated load, with static trim Excludes component temperature coefficient For load transients down to 0% rated load, with dynamic trimming RCOUT-EXT At 10 kHz, excludes component tolerances Output capacitance (external) COUT-EXT Output capacitance (external) COUT-EXT-TRANS Output capacitance (external) Output capacitance, ESR (ext.) COUT-EXT- DCM™ DC-DC Converter Rev 1.0 Page 5 of 23 08/2017 1000 10000 µF 1000 10000 µF 10000 10000 µF 10 mΩ DCM3623x50M31C2y7z Electrical Specifications (cont.) Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade. Attribute Symbol Conditions / Notes Min Typ Max Unit 40 ms Power Output Specifications (Cont.) Initialization delay tINIT See state diagram 25 Output turn-on delay tON From rising edge EN, with VIN pre-applied. See timing diagram 200 Output turn-off delay tOFF From falling edge EN. See timing diagram Soft start ramp time tSS At full rated resistive load, with min COUT-EXT. VOUT threshold for max rated load current IOUT at startup Monotonic soft-start threshold voltage Minimum required disabled duration Minimum required disabled duration for predictable restart Voltage deviation (transient) Settling time VOUT-FL-THRESH IOUT-START VOUT-MONOTONIC 600 220 During startup, VOUT must achieve this threshold before output can support full rated current Max load current at startup while VOUT is below VOUT-FL_THRESH Output voltage rise becomes monotonic with 25% of preload once it crosses VOUT-MONOTONIC µs µs ms 14.0 3.08 V A 12.5 V tOFF-MIN This refers to the minimum time a module needs to be in the disabled state before it will attempt to start via EN 2 ms tOFF-MONOTONIC This refers to the minimum time a module needs to be in the disabled state before it is guaranteed to exhibit monotonic soft-start and have predictable startup timing 100 ms %VOUT-TRANS tSETTLE Minimum COUT_EXT (10 ↔ 90% load step). <10 % 12.0 ms Powertrain Protections Input Voltage Initialization threshold VIN-INIT Threshold to start tINIT delay Input Voltage Reset threshold VIN-RESET Input undervoltage lockout threshold VIN-UVLO- Input undervoltage recovery threshold VIN-UVLO+ Input overvoltage lockout threshold VIN-OVLO+ Input overvoltage recovery threshold VIN-OVLO- See Timing diagram Output overvoltage threshold VOUT-OVP Output overvoltage threshold VOUT-OVP-LL Minimum current limited VOUT VOUT-UVP Overtemperature threshold (internal) TINT-OTP Power limit tOVLO-SW VIN overvoltage response time tOVLO VIN undervoltage response time tUVLO Short circuit, or temperature fault recovery time 3 tSC tFAULT V V 12.00 See Timing diagram 14.50 V 16.00 V 60 V 50 V From 25% to 100% load. Latched shutdown 35.50 V From 0% to 25% load. Latched shutdown 36.50 V Over all operating steady-state line and trim conditions 14.00 125 750 Independent of fault logic 1.5 For fault logic only Powertrain on, operational state See Timing diagram DCM™ DC-DC Converter Rev 1.0 Page 6 of 23 08/2017 V °C PLIM VIN overvoltage to cessation of powertrain switching Short circuit response time Latching faults will clear once VIN falls below VIN-RESET 6 1 W µs 200 µs 100 ms 200 µs s DCM3623x50M31C2y7z Signal Specifications Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade. Enable: EN • The EN pin enables and disables the DCM converter; when held low the unit will be disabled. • The EN pin has an internal pull-up to VCC and is referenced to the -IN pin of the converter. SIGNAL TYPE DIGITAL INPUT STATE Any ATTRIBUTE SYMBOL CONDITIONS / NOTES MIN NOM MAX UNIT 2.31 V EN enable threshold VENABLE-EN EN disable threshold VENABLE-DIS 0.99 VCC 3.21 3.30 3.39 V RENABLE-INT 9.5 10.0 10.5 kΩ Internally generated VCC EN internal pull up resistance to VCC V Trim: TR • The TR pin enables and disables trim functionality when VIN is initially applied to the DCM converter. When Vin first crosses VIN-UVLO+, the voltage on TR determines whether or not trim is active. • If TR is not floating at power up and has a voltage less than TR trim enable threshold, trim is active. • If trim is active, the TR pin provides dynamic trim control with at least 30Hz of -3dB control bandwidth over the output voltage of the DCM converter. • The TR pin has an internal pull-up to VCC and is referenced to the -IN pin of the converter. SIGNAL TYPE DIGITAL INPUT ANALOG INPUT STATE ATTRIBUTE SYMBOL TR trim disable threshold VTRIM-DIS Trim disabled when TR above this threshold at power up TR trim enable threshold VTRIM-EN Trim enabled when TR below this threshold at power up Internally generated VCC VCC 3.21 3.30 3.39 V TR pin functional range VTRIM-RANGE 0.00 2.14 3.16 V Startup Operational with Trim enabled VOUT referred TR pin resolution VOUT-RES TR internal pull up resistance to VCC RTRIIM-INT CONDITIONS / NOTES MIN NOM MAX UNIT 3.20 V 3.15 With VCC = 3.3 V V 34 9.5 10.0 mV 10.5 kΩ Fault: FT • The FT pin is a Fault flag pin. • When the module is enabled and no fault is present, the FT pin does not have current drive capability. • Whenever the powertrain stops (due to a fault protection or disabling the module by pulling EN low), the FT pin output Vcc and provides current to drive an external ciruit. • When module starts up, the FT pin is pulled high to VCC during microcontroller initialization and will remain high until soft start process starts. SIGNAL TYPE STATE Any DIGITAL OUTPUT FT Active ATTRIBUTE FT internal pull up resistance to VCC SYMBOL RFAULT-INT FT voltage VFAULT-ACTIVE FT current drive capability IFAULT-ACTIVE FT response time CONDITIONS / NOTES tFT-ACTIVE At rated current drive capability Over-load beyond the ABSOLUTE MAXIMUM ratings may cause module damage Delay from cessation of switching to FT Pin Active DCM™ DC-DC Converter Rev 1.0 Page 7 of 23 08/2017 MIN NOM MAX UNIT 474 499 524 kΩ 3.0 V 4 mA 200 µs DCM3623x50M31C2y7z High Level Functional State Diagram Conditions that cause state transitions are shown along arrows. Sub-sequence activities listed inside the state bubbles. Application of VIN VIN > VIN-INIT INITIALIZATION SEQUENCE EN = False tMIN-OFF delay NON LATCHED FAULT tOFF ult Fa oved m Re Powertrain: Stopped FT = True tINIT delay Powertrain: Stopped FT = True Powertrain: Stopped FT = True EN = True and No Faults tON delay EN = False tOFF delay In p In ut O pu V tU L VL O o O r VIN > VIN-UVLO+ and not Over-temp TR mode latched STANDBY or O L V LO t O UV u t p In npu I EN = False tOFF-MIN delay SOFT START VOUT Ramp Up tss delay Powertrain: Active FT = False RUNNING tSS Expiry Ou Regulates VOUT Powertrain: Active FT = False tpu or mp r-te P Ove put UV Out REINITIALIZATION SEQUENCE tINIT delay Powertrain: Stopped FT = True Fault Removed Ov e Ou r-tem tpu p t U or VP VP tO pu ut O tO VP NON LATCHED FAULT tFAULT Powertrain: Stopped FT = True LATCHED FAULT EN = False DCM™ DC-DC Converter Rev 1.0 Page 8 of 23 08/2017 Powertrain: Stopped FT = True Output Input DCM™ DC-DC Converter Rev 1.0 Page 9 of 23 08/2017 FT ILOAD FULL LOAD IOUT VOUT VOUT-UVP FULL LOAD VOUT-NOM TR VTR-DIS EN VIN VIN-UVLO+/VIN-INIT VIN-OVLO+/- tINIT tON 1 Input Power On - Trim Inactive tSS 2 3 Ramp to TR Full Load Ignored tOFF tMIN_OFF 4 EN Low tSS tON 5 EN High tOFF 6 Input OVLO tSS tOFF 7 Input UVLO tSS tOFF 8 Input returned to zero DCM3623x50M31C2y7z Timing Diagrams Module Inputs are shown in blue; Module Outputs are shown in brown. Output Input DCM™ DC-DC Converter Rev 1.0 Page 10 of 23 08/2017 FT ILOAD FULL LOAD IOUT VOUT VOUT-UVP VOUT-NOM FULL LOAD TR VTR = nom VTR-EN EN VIN VIN-UVLO+/VIN-INIT VIN-OVLO+/- tINIT tON 9 Input Power On - Trim Active tSS VOUT-OVP 10 Vout based on VTR tOFF 11 Load dump and reverse current tINIT tON tSS 12 Vout OVP (primary sensed) 13 Latched fault cleared RLOAD tIOUT-LIM 14 Current Limit with Resistive Load tFAULT 15 Resistive Load with decresing R tINIT 16 Overload induced Output UVP tON tSS DCM3623x50M31C2y7z Timing Diagrams (Cont.) Module Inputs are shown in blue; Module Outputs are shown in brown. DCM3623x50M31C2y7z Typical Performance Characteristics The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data. Figure 3 — Disabled power dissipation vs. VIN Figure 6 — Full Load Efficiency vs. VIN, at low trim Figure 4 — No load power dissipation vs. VIN, at nominal trim Figure 7 — Full Load Efficiency vs. VIN, at nominal trim Figure 5 — Ideal VOUT vs. load current, at 25°C case Figure 8 — Full Load Efficiency vs. VIN, at high trim DCM™ DC-DC Converter Rev 1.0 Page 11 of 23 08/2017 DCM3623x50M31C2y7z Typical Performance Characteristics (cont.) The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data. Figure 9 — Efficiency and power dissipation vs.load at TCASE = -40°C, nominal trim Figure 12 — Nominal powertrain switching frequency vs. load, at nominal trim Figure 10 — Efficiency and power dissipation vs.load at TCASE = 25°C, nominal trim Figure 13 — Effective internal input capacitance vs. applied voltage Figure 11 — Efficiency and power dissipation vs.load at TCASE = 90°C, nominal trim Figure 14 — Startup from EN, VIN = 28 V, COUT_EXT = 10000 µF, RLOAD = 2.450 Ω DCM™ DC-DC Converter Rev 1.0 Page 12 of 23 08/2017 DCM3623x50M31C2y7z Typical Performance Characteristics (cont.) The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data. Figure 15 — Nominal powertrain switching frequency vs. load, Figure 16 — Output voltage ripple, VIN = 28 V, VOUT = 28.0 V, COUT_EXT = 1000 µF, RLOAD = 2.450 Ω at nominal VIN DCM™ DC-DC Converter Rev 1.0 Page 13 of 23 08/2017 DCM3623x50M31C2y7z General Characteristics Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade. Attribute Symbol Conditions / Notes Min Typ Max Unit Mechanical Length L 38.34/[1.509] 38.72/[1.524] 39.10/[1.539] mm/[in] Width W 22.67/[0.893] 22.8/[0.898] 22.93/[0.903] mm/[in] Height H 7.11/[0.28] 7.21/[0.284] 7.31/[0.288] mm/[in] Volume Vol Weight W Lead finish No heat sink 6.41/[0.39] cm3/[in3] 24.0/[0.85] g/[oz] Nickel 0.51 2.03 Palladium 0.02 0.15 Gold 0.003 0.051 T-Grade -40 125 °C M-Grade -55 125 °C µm Thermal Operating internal temperature Thermal resistance top side Thermal resistance leads Thermal resistance bottom side TINT θINT-TOP θINT-LEADS θINT-BOTTOM Estimated thermal resistance to maximum temperature internal component from 2.28 °C/W 5.39 °C/W 2.57 °C/W 17.7 Ws/°C isothermal top Estimated thermal resistance to maximum temperature internal component from isothermal leads Estimated thermal resistance to maximum temperature internal component from isothermal bottom Thermal capacity Assembly Storage temperature TST HBM ESD rating CDM T-Grade -40 125 °C M-Grade -65 125 °C Method per Human Body Model Test ESDA/JEDEC JDS-001-2012 Charged Device Model JESD22-C101E CLASS 1C V CLASS 2 Soldering [1] Peak temperature top case [1] For further information, please contact factory applications Product is not intended for reflow solder attach. DCM™ DC-DC Converter Rev 1.0 Page 14 of 23 08/2017 135 °C DCM3623x50M31C2y7z General Characteristics (Cont.) Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade. Attribute Symbol Conditions / Notes Min Typ Max Unit Safety Dielectric Withstand Test VHIPOT IN to OUT 2250 Vdc IN to CASE 2250 Vdc OUT to CASE 707 Vdc Reliability MIL-HDBK-217 FN2 Parts Count 25°C Ground Benign, Stationary, Indoors / MTBF 3.39 MHrs 5.68 MHrs Computer Telcordia Issue 2, Method I Case 3, 25°C, 100% D.C., GB, GC Agency Approvals cTÜVus, EN 60950-1 Agency approvals/standards cURus, UL 60950-1 CE Marked for Low Voltage Directive and RoHS Recast Directive, as applicable DCM™ DC-DC Converter Rev 1.0 Page 15 of 23 08/2017 DCM3623x50M31C2y7z Pin Functions The DCM will latch trim behavior at application of VIN (once VIN exceeds VIN-UVLO+), and persist in that same behavior until loss of input voltage. n At application of VIN, if TR is sampled at above VTRIM-DIS, the module will latch in a non-trim mode, and will ignore the TR input for as long as VIN is present. +IN, -IN Input power pins. -IN is the reference for all control pins, and therefore a Kelvin connection for the control signals is recommended as close as possible to the pin on the package, to reduce effects of voltage drop due to -IN currents. n At application of VIN, if TR is sampled at below VTRIM-EN, the TR will serve as an input to control the real time output voltage, relative to full load, 25°C. It will persist in this behavior until VIN is no longer present. +OUT, -OUT Output power pins. If trim is active when the DCM is operating, the TR pin provides dynamic trim control at a typical 30 Hz of -3dB bandwidth over the output voltage. TR also decreases the current limit threshold when trimming above VOUT-NOM. EN (Enable) This pin enables and disables the DCM converter; when held low the unit will be disabled. It is referenced to the -IN pin of the converter. The EN pin has an internal pull-up to VCC through a 10 kΩ resistor. FT (Fault) n Output enable: When EN is allowed to pull up above the enable The FT pin provides a Fault signal. threshold, the module will be enabled. If leaving EN floating, it is pulled up to VCC and the module will be enabled. Anytime the module is enabled and has not recognized a fault, the FT pin is inactive. FT has an internal 499 kΩ pull-up to Vcc, therefore a shunt resistor, RSHUNT, of approximately 50 kΩ can be used to ensure the LED is completly off when there is no fault, per the diagram below. n Output disable: EN may be pulled down externally in order to disable the module. n EN is an input only, it does not pull low in the event of a fault. Whenever the powertrain stops (due to a fault protection or disabling the module by pulling EN low), the FT pin becomes active and provides current to drive an external circuit. TR (Trim) The TR pin is used to select the trim mode and to trim the output voltage of the DCM converter. The TR pin has an internal pull-up to VCC through a 10.0 kΩ resistor. When active, FT pin drives to VCC, with up to 4 mA of external loading. Module may be damaged from an over-current FT drive, thus a resistor in series for current limiting is recommended. The FT pin becomes active momentarily when the module starts up. Typical External Circuits for Signal Pins (TR, EN, FT) Vcc Vcc 10k Vcc Output Voltage Reference, Current Limit Reference and Soft Start Control TR 499k Fault Monitoring 10k Soft Start and Fault Monitoring FT EN RSERIES SW RTRIM RSHUNT Kelvin -IN connection DCM™ DC-DC Converter Rev 1.0 Page 16 of 23 08/2017 DCM3623x50M31C2y7z Design Guidelines Use 0 V for ∆VOUT-LL when load is above 5% of rated load. See section on light load boosting operation for light load effects on output voltage. Building Blocks and System Design The DCM™ converter input accepts the full 16 to 50 V range, and it generates an isolated trimmable 28.0 Vdc output. Output Current Limit The DCM features a fully operational current limit which effectively keeps the module operating inside the Safe Operating Area (SOA) for all valid trim and load profiles. The current limit approximates a “brick wall” limit, where the output current is prevented from exceeding the current limit threshold by reducing the output voltage via the internal error amplifier reference. The current limit threshold at nominal trim and below is typically 115% of rated output current, but it can vary between 100% to 123%. In order to preserve the SOA, when the converter is trimmed above the nominal output voltage, the current limit threshold is automatically reduced to limit the available output power. The DCM converter provides a tightly regulated output voltage with regulation accuracy of ± 1% for all line conditions and for any load above 10% the rated load. The DCM3623x50M31C2y7z is designed to be used in applications where the output power requirements are up to 320 W. Soft Start When the DCM starts, it will go through a soft start. The soft start routine ramps the output voltage by modulating the internal error amplifier reference. This causes the output voltage to approximate a piecewise linear ramp. The output ramp finishes when the voltage reaches either the nominal output voltage, or the trimmed output voltage in cases where trim mode is active. When the output current exceeds the current limit threshold, current limit action is held off by 1ms, which permits the DCM to momentarily deliver higher peak output currents to the load. Peak output power during this time is still constrained by the internal Power Limit of the module. The fast Power Limit and relatively slow Current Limit work together to keep the module inside the SOA. Delaying entry into current limit also permits the DCM to minimize droop voltage for load steps. During soft-start, the maximum load current capability is reduced. Until Vout achieves at least VOUT-FL-THRESH, the output current must be less than IOUT-START in order to guarantee startup. Note that this is current available to the load, above that which is required to charge the output capacitor. Sustained operation in current limit is permitted, and no derating of output power is required. Trim Mode and Output Trim Control When the input voltage is initially applied to a DCM, and after tINIT elapses, the trim pin voltage VTR is sampled. The TR pin has an internal pull up resistor to VCC, so unless external circuitry pulls the pin voltage lower, it will pull up to VCC. If the initially sampled trim pin voltage is higher than VTRIM-DIS, then the DCM will disable trimming as long as the VIN remains applied. In this case, for all subsequent operation the output voltage will be programmed to the nominal. This minimizes the support components required for applications that only require the nominal rated Vout, and also provides the best output setpoint accuracy, as there are no additional errors from external trim components Some applications may benefit from well matched current distribution, in which case fine tuning sharing via the trim pins permits control over sharing. The DCM does not require this for proper operation, due to the power limit and current limit behaviors described here. Current limit can reduce the output voltage to as little as the UVP threshold (VOUT-UVP). Below this minimum output voltage compliance level, further loading will cause the module to shut down due to the output undervoltage fault protection. Line Impedance, Input Slew rate and Input Stability Requirements Connect a high-quality, low-noise power supply to the +IN and –IN terminals. Additional capacitance may have to be added between +IN and –IN to make up for impedances in the interconnect cables as well as deficiencies in the source. If at initial application of VIN, the TR pin voltage is prevented from exceeding VTRIM-EN, then the DCM will activate trim mode, and it will remain active for as long as VIN is applied. VOUT set point can be calculated using the equation below: VOUT-FL = 19.50 + (13.110 • VTR/VCC) (1) Excessive source impedance can bring about system stability issues for a regulated DC-DC converter, and must either be avoided or compensated by filtering components. A 1000 µF input capacitor is the minimum recommended in case the source impedance is insufficient to satisfy stability requirements. Note that the trim mode is not changed when a DCM recovers from any fault condition or being disabled. Module performance is guaranteed through output voltage trim range VOUT-TRIMMING. If VOUT is trimmed above this range, then certain combinations of line and load transient conditions may trigger the output OVP. Additional information can be found in the filter design application note: www.vicorpower.com/documents/application_notes/vichip_appnote23.pdf Please refer to this input filter design tool to ensure input stability: http://app2.vicorpower.com/filterDesign/intiFilter.do. Overall Output Voltage Transfer Function Taking trim (equation 1) into account, the general equation relating the DC VOUT to programmed trim (when active), load is given by: VOUT = 19.50 + (13.110 • VTR/VCC) + ∆VOUT-LL Ensure that the input voltage slew rate is less than 1V/us, otherwise a pre-charge circuit is required for the DCM input to control the input voltage slew rate and prevent overstress to input stage components. (2) Finally, note that when the load current is below 5% of the rated capacity, there is an additional ∆V which may add to the output voltage, depending on the line voltage which is related to light load boosting. Please see the section on light load boosting below for details. DCM™ DC-DC Converter Rev 1.0 Page 17 of 23 08/2017 DCM3623x50M31C2y7z immediately stops switching, and the output voltage of the converter falls. The converter remains disabled for a time tFAULT. Once recovered and provided the converter is still enabled, the powertrain will again enter the soft start sequence after tINIT and tON. Input Fuse Selection The DCM is not internally fused in order to provide flexibility in configuring power systems. Input line fusing is recommended at the 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: Temperature Fault Protections (OTP) The fault logic monitors the internal temperature of the converter. If the measured temperature exceeds TINT-OTP, a temperature fault is registered. As with the under voltage fault protection, once a temperature fault is registered, the powertrain immediately stops switching, the output voltage of the converter falls, and the converter remains disabled for at least time tFAULT. Then, the converter waits for the internal temperature to return to below TINT-OTP before recovering. Provided the converter is still enabled, the DCM will restart after tINIT and tON. n Current rating (usually greater than the DCM converter’s maximum current) n Maximum voltage rating (usually greater than the maximum possible input voltage) n Ambient temperature n Breaking capacity per application requirements n Nominal melting I2t n Recommended fuse: See Agency Approvals for Recommended Fuse Output Overvoltage Fault Protection (OVP) The converter monitors the output voltage during each switching cycle by a corresponding voltage reflected to the primary side control circuitry. If the primary sensed output voltage exceeds VOUT-OVP, the OVP fault protection is triggered. The control logic disables the powertrain, and the output voltage of the converter falls. http://www.vicorpower.com/dc-dc/isolatedregulated/dcm#Documentation Fault Handling Input Undervoltage Fault Protection (UVLO) The converter’s input voltage is monitored to detect an input under voltage condition. If the converter is not already running, then it will ignore enable commands until the input voltage is greater than VIN-UVLO+. If the converter is running and the input voltage falls below VIN-UVLO-, the converter recognizes a fault condition, the powertrain stops switching, and the output voltage of the unit falls. This type of fault is latched, and the converter will not start again until the latch is cleared. Clearing the fault latch is achieved by either disabling the converter via the EN pin, or else by removing the input power such that the input voltage falls below VIN-INIT. External Output Capacitance The DCM converter internal compensation requires a minimum external output capacitor. An external capacitor in the range of 1000 to 10000 µF with ESR of 10 mΩ is required, per DCM for control loop compensation purposes. Input voltage transients which fall below UVLO for less than tUVLO may not be detected by the fault proection logic, in which case the converter will continue regular operation. No protection is required in this case. However some DCM models require an increase to the minimum external output capacitor value in certain loading and trim condition. In applications where the load can go below 5% of rated load but the output trim is held constant, the range of output capacitor required is given by COUT-EXT-TRANS in the Electrical Specifications table. If the load can go below 5% of rated load and the DCM output trim is also dynamically varied, the range of output capacitor required is given by COUT-EXT-TRANS-TRIM in the Electrical Specifications table. Once the UVLO fault is detected by the fault protection logic, the converter shuts down and waits for the input voltage to rise above VIN-UVLO+. Provided the converter is still enabled, it will then restart. Input Overvoltage Fault Protection (OVLO) The converter’s input voltage is monitored to detect an input over voltage condition. When the input voltage is more than the VIN-OVLO+, a fault is detected, the powertrain stops switching, and the output voltage of the converter falls. After an OVLO fault occurs, the converter will wait for the input voltage to fall below VIN-OVLO-. Provided the converter is still enabled, the powertrain will restart. Light Load Boosting Under light load conditions, the DCM converter may operate in light load boosting depending on the line voltage. Light load boosting occurs whenever the internal power consumption of the converter combined with the external output load is less than the minimum power transfer per switching cycle. In order to maintain regulation, the error amplifier will switch the powertrain off and on repeatedly, to effectively lower the average switching frequency, and permit operation with no external load. During the time when the power train is off, the module internal consumption is significantly reduced, and so there is a notable reduction in no-load input power in light load boosting. When the load is less than 5% of rated Iout, the output voltage may rise by a maximum of 5.01 V, above the output voltage calculated from trim, temperature, and load line conditions. The powertrain controller itself also monitors the input voltage. Transient OVLO events which have not yet been detected by the fault sequence logic may first be detected by the controller if the input slew rate is sufficiently large. In this case, powertrain switching will immediately stop. If the input voltage falls back in range before the fault sequence logic detects the out of range condition, the powertrain will resume switching and the fault logic will not interrupt operation Regardless of whether the powertrain is running at the time or not, if the input voltage does not recover from OVLO before tOVLO, the converter fault logic will detect the fault. Output Undervoltage Fault Protection (UVP) The converter determines that an output overload or short circuit condition exists by measuring its primary sensed output voltage and the output of the internal error amplifier. In general, whenever the powertrain is switching and the primary-sensed output voltage falls below VOUT-UVP threshold, a short circuit fault will be registered. Once an output undervoltage condition is detected, the powertrain DCM™ DC-DC Converter Rev 1.0 Page 18 of 23 08/2017 DCM3623x50M31C2y7z Thermal Design Based on the safe thermal operating area shown in page 5, the full rated power of the DCM3623x50M31C2y7z can be processed provided that the top, bottom, and leads are all held below 95°C. These curves highlight the benefits of dual sided thermal management, but also demonstrate the flexibility of the Vicor ChiP platform for customers who are limited to cooling only the top or the bottom surface. Thermal Resistance Top Thermal Resistance Bottom θINT-BOTTOM°C / W Power Dissipation (W) The OTP sensor is located on the top side of the internal PCB structure. Therefore in order to ensure effective over-temperature fault protection, the case bottom temperature must be constrained by the thermal solution such that it does not exceed the temperature of the case top. Thermal Resistance Top TCASE_BOTTOM(°C) + – TCASE_TOP(°C) Thermal Resistance Bottom θINT-BOTTOM°C / W Power Dissipation (W) Thermal Resistance Leads TCASE_BOTTOM(°C) θINT-LEADS°C / W TLEADS(°C) TCASE_TOP(°C) Figure 19 shows a scenario where there is no bottom side and leads cooling. In this case, the heat flow path to the bottom is left open and the equations now simplify to: TINT – PD1 • θINT-TOP = TCASE_TOP PDTOTAL = PD1 θINT-LEADS°C / W TLEADS(°C) + – TCASE_TOP(°C) + – Figure 19 — One side cooling thermal model Thermal Resistance Leads + – + – MAX INTERNAL TEMP θINT-TOP°C / W MAX INTERNAL TEMP θINT-BOTTOM°C / W Power Dissipation (W) TLEADS(°C) TINT – PD1 • θINT-TOP = TCASE_TOP TINT – PD3 • θINT-LEADS = TLEADS PDTOTAL = PD1 + PD3 This analysis provides an estimate of heat flow through the various pathways as well as internal temperature. Thermal Resistance Bottom θINT-LEADS°C / W TCASE_BOTTOM(°C) Figure 18 shows a scenario where there is no bottom side cooling. In this case, the heat flow path to the bottom is left open and the equations now simplify to: Since the ChiP has a maximum internal temperature rating, it is necessary to estimate this internal temperature based on a real thermal solution. Given that there are three pathways to remove heat from the ChiP, 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 17 shows the "thermal circuit" for a 3623 ChiP DCM, in an application where both case top and case bottom, and leads are cooled. In this case, the DCM power dissipation is PDTOTAL and the three surface temperatures are represented as TCASE_TOP, TCASE_BOTTOM, and TLEADS. This thermal system can now be very easily analyzed with simple resistors, voltage sources, and a current source. θINT-TOP°C / W Thermal Resistance Leads Figure 18 — One side cooling and leads thermal model The ChiP package provides a high degree of flexibility in that it presents three pathways to remove heat from internal power dissipating components. Heat may be removed from the top surface, the bottom surface and the leads. The extent to which these three surfaces are cooled is a key component for determining the maximum power that is available from a ChiP, as can be seen from Figure 17. Thermal Resistance Top MAX INTERNAL TEMP θINT-TOP°C / W + – Figure 17 — Double side cooling and leads thermal model Alternatively, equations can be written around this circuit and analyzed algebraically: TINT – PD1 • θINT-TOP = TCASE_TOP TINT – PD2 • θINT-BOTTOM = TCASE_BOTTOM TINT – PD3 • θINT-LEADS = TLEADS PDTOTAL = PD1+ PD2+ PD3 Where TINT represents the internal temperature and PD1, PD2, and PD3 represent the heat flow through the top side, bottom side, and leads respectively. Figure 20 — Thermal Specified Operating Area: Max Power Dissipation vs. Case Temp for current limited operation DCM™ DC-DC Converter Rev 1.0 Page 19 of 23 08/2017 DCM3623x50M31C2y7z Vicor provides a suite of online tools, including a simulator and thermal estimator which greatly simplify the task of determining whether or not a DCM thermal configuration is sufficient for a given condition. These tools can be found at: www.vicorpower.com/powerbench. DCMs in current limit will operate with higher output current or power than the rated levels. Therefore the Figure 20 Thermal Safe Operating Area plot should be used for loads that drive the DCM in to current limit for sustained operation. Standalone Operation The following Figure 21 shows the configuration of the Enhanced VOUT DCM. An input filter is required to attenuate noise coming from the input source. In case of the excessive line inductance, a properly sized decoupling capacitor CDECOUPLE is required as shown in the following figure. DCM R5 + + VTR R1 VEN FB1 EN C2 R3 F1 +IN -IN FT +IN L1 CDECOUPLE TR C1 R2 +OUT R4 _ _ D1 -IN +OUT L2 COUT-EXT C4 C5 -OUT -OUT Figure 21 — Enhanced VOUT DCM configuration circuit If signal pins (TR, EN, FT) are not used, they can be left floating, and DCM will work in the nominal output condition. When common mode noise in the input side is not a concern, TR and EN can be driven and FT received using -IN as a reference. L1: 1 µH, minimized DCR; R1: 0.3 Ω; C1: Ceramic capacitors in parallel, C1 = 20 µF; L2: L2 ≥ 0.15 µH; R2: 1 Ω; COUT-EXT: electrolytic or tantalum capacitor, 1000 µF ≤ C3 ≤10000 µF; C4, C5: additional ceramic /electrolytic capacitors, if needed for output ripple filtering; In order to help sensitive signal circuits reject potential noise, additional components are recommended: R5: 301 Ω, facilitate noise attenuation for TR pin; FB1, C2: FB1 is a ferrite bead with an impedance of at least 10 Ω at 100MHz. C2 can be a ceramic capacitor of 0.1µF. Facilitate noise attenuation for EN pin. Note: Use an RCR filter network as suggested in the application note AN:030 to reduce the noise on the signal pins. DCM™ DC-DC Converter Rev 1.0 Page 20 of 23 08/2017 DCM3623x50M31C2y7z DCM Module Product Outline Drawing Recommended PCB Footprint and Pinout 38.72±.38 1.524±.015 11.43 .450 19.36 .762 0 1.52 .060 (2) PL. 11.40 .449 0 0 22.80±.13 .898±.005 1.02 .040 (3) PL. 0 1.52 .060 (4) PL. TOP VIEW (COMPONENT SIDE) .05 [.002] 7.21±.10 .284±.004 SEATING . PLANE 4.17 .164 (9) PL. 18.60 .732 0 18.60 .732 .41 .016 (9) PL. 8.25 .325 8.00 .315 2.75 .108 0 0 2.75 .108 1.38 .054 4.13 .162 1.38 .054 8.00 .315 0 8.25 .325 8.00±.08 .315±.003 4.13±.08 .162±.003 1.38±.08 .054±.003 +IN 0 2.03 .080 PLATED THRU .25 [.010] ANNULAR RING (2) PL. 2.75±.08 .108±.003 -OUT TR 0 EN FT 8.00±.08 .315±.003 8.25±.08 .325±.003 +OUT -IN +OUT 2.75±.08 .108±.003 -OUT 8.25±.08 .325±.003 0 1.38±.08 .054±.003 0 18.60±.08 .732±.003 1.52 .060 PLATED THRU .25 [.010] ANNULAR RING (3) PL. 18.60±.08 .732±.003 BOTTOM VIEW RECOMMENDED HOLE PATTERN (COMPONENT SIDE) NOTES: 1- RoHS COMPLIANT PER CST-0001 LATEST REVISION. DCM™ DC-DC Converter Rev 1.0 Page 21 of 23 08/2017 2.03 .080 PLATED THRU .38 [.015] ANNULAR RING (4) PL. DCM3623x50M31C2y7z Revision History Revision Date 1.0 08/31/17 Description Initial release Page Number(s) n/a DCM™ DC-DC Converter Rev 1.0 Page 22 of 23 08/2017 DCM3623x50M31C2y7z 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. Visit http://www.vicorpower.com/dc-dc/isolated-regulated/dcm for the latest product information. Vicor’s Standard Terms and Conditions and Product Warranty All sales are subject to Vicor’s Standard Terms and Conditions of Sale, and Product Warranty which are available on Vicor’s webpage (http://www.vicorpower.com/termsconditionswarranty) or upon request. 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: RE40,072; 7,561,446; 7,920,391; 7,782,639; 8,427,269; 6,421,262 and other patents pending. Contact Us: http://www.vicorpower.com/contact-us Vicor Corporation 25 Frontage Road Andover, MA, USA 01810 Tel: 800-735-6200 Fax: 978-475-6715 www.vicorpower.com email Customer Service: [email protected] Technical Support: [email protected] ©2017 Vicor Corporation. All rights reserved. The Vicor name is a registered trademark of Vicor Corporation. All other trademarks, product names, logos and brands are property of their respective owners. DCM™ DC-DC Converter Rev 1.0 Page 23 of 23 08/2017