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UG:017 

vicorpower.com 

Applications Engineering: 800 927.9474 

Page 16

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Both the visible LED and the opco-coupler draw current from the FT node in a fault condition. The FT 
pin on the DCM has limited drive-high capabilities, and so care must be taken to avoid excess loading 
of the pin. To avoid overload, do not configure J10 to use both the LED and opto-coupler indicators 
simultaneously. When connecting external circuitry or test equipment to the FT test point, ensure that 
the maximum load on the FT node is within the DCM datasheet ratings.

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In a parallel setup using the J02 & J03 paralleling connectors, all boards besides the top one should 
have the fault jumper select block at J10 open.

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When using the opto-coupler, the status of the FT node can be easily transferred to the secondary side 
of the DCM(s) isolation boundary. To resolve the fault state on the secondary side, the collector side 
of the opto requires a bias voltage. A 5V bench supply should be connected between the “+5V” and 
“SEC_SG”  testpoints. With no fault present, “FT_SEC” will be at 0V, and when a fault occurs and the 
opto-coupler is active, “FT_SEC” will pull up to 5V, relative to SEC_SG.

Chassis Ground

The heatsink assembly of the DCM is connected to the CHASSIS_GND node of the board, as well as the 
y-caps from each power connection of the DCM. A connection from the CHASSIS_GND lug to earth 
ground is required.

Paralleling

The paralleling and sharing performance of multiple DCMs can be easily demonstrated by stacking 
multiple evaluation boards and interconnecting the inputs and outputs with standoffs to create a 
parallel array. The DCM uses a negative load-line to implement wireless droop-sharing in an array. Each 
DCM in an array operates in the same way as it does as a stand-alone unit. With equal trim conditions, 
the load is effectively shared across multiple DCMs. Mismatches in this case are modest, and are further 
canceled by an effective negative voltage vs. temperature coefficient. See the DCM datasheet for more 
detail on load line and tempco. DCMs in an array require no derating of maximum output power or 
current.

DCMs in an array with mismatched trim conditions will not share the load equally at light- to 
moderate-load conditions. As the load increases, one or more DCMs (starting with those with the 
highest programmed output trim voltage) will go into current limit and their contribution to the overall 
output current will plateau. For DCMs, current limit is not a fault condition, rather it is a valid constant-
current mode of operation and a DCM in current limit will provide constant current to the load. As long 
as the load does not exceed the maximum load rating of the array of DCMs, the output voltage will 
continue to be regulated by any remaining DCMs still in constant voltage mode. Even with mismatched 
trim conditions, the array can be safely loaded up to the full rated array capacity.

The following connections and settings should be used for an array of DCM evaluation boards:

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All DCMs in a parallel array must be the same model.

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The boards should be physically stacked using metal standoffs at the +IN & –IN lugs, the +OUT & 
–OUT lugs, and the CHASSIS_GND lug. This also connects these nodes electrically so that a single 
source, single load, and earth ground connection can be made to the system.

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The +IN lugs are not required to be connected together for an array of DCMs. The wireless  
sharing does not require the same differential input voltage be present on all DCMs in the array.  
In some applications dissimilar input voltages may be needed, which is fully supported.

Summary of Contents for 3623

Page 1: ...les output trimming and the output trim is programmed to the nominal rated VOUT 2 Variable trim operation on board variable resistor The trim pin voltage is ratiometric with a rheostat working against a pull up resistor inside the DCM to VCC 3 Variable trim operation off board control The trim pin voltage is controlled via external programming control which is referenced to the IN of each specific...

Page 2: ... high temperatures n n Remove power and use caution when connecting and disconnecting test probes and interface lines to avoid inadvertent short circuits and contact with hot surfaces n n Never use a jumper in place of the fuse n n When testing electronic products always use approved safety glasses Follow good laboratory practice and procedures n n Avoid creating ground loops when making measureme...

Page 3: ...acitors for additional source decoupling Note The filtering used in the eval board is for demonstration purposes only and might not be the optimal solution for all applications For optimal filter design for parallel array application consult the datasheet of the DCM in use and the online filter design tool at http app2 vicorpower com filterDesign intiFilter do 4 Basic output filtering including so...

Page 4: ...Sized for 10 hardware Use these lugs to connect the output directly to the load 8 Output oscilloscope probe Jack J01 Used for making accurate scope measurements of the output voltage e g ripple The jack is directly compatible with many common passive voltage probes models Remove the grounding lead and insulating barrel of the probe and insert the probe tip and barrel directly into the jack ensurin...

Page 5: ...UG 017 vicorpower com Applications Engineering 800 927 9474 Page 5 Figure 1 3623 DCM evaluation board photo top side Figure 2 4623 DCM evaluation board photo top side ...

Page 6: ...SG using an external source PRI_EN Testpoint to measure the ENABLE signal relative to PRI_SG EXT_TR Testpoint to drive the TRIM signal relative to PRI_SG using an external source PRI_TR Testpoint to measure the TRIM signal relative to PRI_SG PRI_FT Testpoint to measure the FAULT signal relative to PRI_SG Name Description OUT_DCM OUT_DCM Output voltage test points provide Kelvin connection to outpu...

Page 7: ...0603 R22 0603 R23 SEC_SG FT_SEC TP29 1206 FB1 0603 R02 0603 R05 CHASSIS_GND J108 0603 R32 IN_DCM TP5 IN_DCM TP7 OUT_DCM TP6 OUT_DCM TP9 PRI_SG 0603 R01 EXT_TRIM TP28 PARALLELING C ONNECTORS IN_FUSED TP2 IN TP27 IN IN_FILT TP100 IN_DCM IN_DCM IN_FILT TP3 AD DA CL PRI_EN PRI_FT PRI_TR 0402 C23 0402 R503 0603 R118 PRI_SER_OUT 0603 R119 0603 R120 PRI_SER_IN PRI_PWM PRI_FT TP32 PRI_TR TP30 PRI_EN TP31 ...

Page 8: ...0402 R504 0402 C24 0402 R505 0402 C25 PRI_SG 29581 S101 TP101 29581 S102 29581 S103 29581 S104 OUT_DCM OUT_DCM F01 3 1 4 2 J02 1 2 5 4 3 6 M02 0603 R21 PRI_SG 0603 R22 0603 R23 SEC_SG FT_SEC TP29 1206 FB1 0603 R02 0603 R05 CHASSIS_GND J108 0603 R32 2010 R25 IN_DCM TP5 IN_DCM TP7 OUT_DCM TP6 OUT_DCM TP9 1 1 3 3 2 2 R26 RES TRIM POT 500K OHM 1 2W 10 TH PRI_SG 0603 R01 EXT_TRIM TP28 PARALLELING C ONN...

Page 9: ...18 R119 R120 R504 TP2 TP3 TP27 TP33 TP34 F01 F02 J01 Figure 6 4623 DCM evaluation board assembly drawing top side TOP VIEW U201 R204 R203 R202 R201 L202 L201 J204 D202 C201 J105 J106 J104 J107 C206 L203 L204 R205 R206 R207 R208 R214 R223 R224 R225 R226 Q200 Q201 R227 R228 R229 R230 S101 S102 S103 S104 J504 TP1 SW13 R243 R242 R241 R240 R124 R26 R25 R12 R11 L211 L210 TP29 TP32 TP31 TP8 TP28 TP26 TP4...

Page 10: ...ADAPTER 3 5mm PROBE TESTPATH 131 5031 00 L01 Board specific See table 4 BOMs L02 IND 0 33µH 20 50A WURTH 744309033 M02 IC 6 PIN OPTO VISHAY CNY17 3X017T R02 R04 R05 R18 R19 R20 RES 0 OHM JUMPER 0603 KOA RK73Z1JTTD PS01 Design specific See table 5 BOMs VICOR R08 RES 1 OHM W 5 1206 KOA RK73B2BTTE1R0J R16 RES 250 mOHM 1W 2512 VISHAY WSL2512R2500FEA R09 R21 RES 1 KOHM 1 10W 5 0603 KOA RK73B1JTTD102J R...

Page 11: ... L01 IND 0 33µH 20 50A WURTH 744309033 HS01 HS02 3623 DUAL HTSNK VICOR 40526 S101 RES 0 OHM JUMPER 1612 COPPER EXCELTOOL DIE 29581 CIN H01 H02 CAP ALEL 680µF 20 63V RADIAL 18 X 20 UNITED CHEMI CON ELXZ630ELL681MM20S Reference Designator Description Manufacturer Manufacturer Part Number 4623 board components C07 C14 CAP X7R 4700pF 10 2kV 1210 KEMET C1210C472KGRAC7800 C15 C22 CAP X7T 0 47µF 10 630V ...

Page 12: ...M3623T50M17C2M00 F02 FUSE 30A 125V AXIAL LITTELFUSE 324 030P C201 CAP ALEL 2200µF 20 25V RADIAL 16 x 25 NICHICON UPW1E222MHD Evaluation board numbers DCM3623E50M26C2M00 DCM3623E50M31C2M00 PS01 DCM 3623 VICOR One of DCM3623T50M26C2M00 DCM3623T50M31C2M00 F01 FUSE 30A 125V AXIAL LITTELFUSE 324 030P C201 CAP ALEL 1000µF 20 50V RADIAL 18 x 20 UNITED CHEMICON EKY 500ELL102MM20S Evaluation board number D...

Page 13: ...BK PCD 5 R C201 CAP ALEL 220µF 20 80V RADIAL 18 x 16 5 NICHICON UPJ1K221MHD6TN Schematic Assembly Drawing and Bill of Materials Cont General BOM rules for various DCM Evaluation Boards n n PS01 This is the Vicor DCM whose part number is coded in the evaluation board part number For example eval board DCM4623ED2K53E0M00 uses DCM4623TD2K53E0M00 n n F01 This is the input fuse See the datas heet for t...

Page 14: ...m bench equipment is powered off n n Connect the input DC power supply positive lead to the IN input lug of the evaluation board connect the input power supply negative lead to the IN input lug of the evaluation board n n Connect the CHASSIS_GROUND lug of the evaluation board to a safety green wire earth ground n n Connect the OUT lug of the evaluation board to the electronic load positive input c...

Page 15: ...e value of the potentiometer 500kΩ This resistance range will generate TR pin voltages which cover the entire functional range of the TR pin Care should be taken to ensure the programmed trim condition is within the rated trim range of the DCM in order for the DCM to meet specifications n n In a parallel setup using the J02 J03 paralleling connectors all boards besides the top one should have the ...

Page 16: ...ay Each DCM in an array operates in the same way as it does as a stand alone unit With equal trim conditions the load is effectively shared across multiple DCMs Mismatches in this case are modest and are further canceled by an effective negative voltage vs temperature coefficient See the DCM datasheet for more detail on load line and tempco DCMs in an array require no derating of maximum output po...

Page 17: ...an be used for coordinated enable and trim control and fault monitoring The enable trim and fault monitor features of the top most board should be used for convenience while the remaining boards should have their jumper blocks depopulated and enable switches set to enable The paralleling wire to board connectors at J02 and J03 are provided to daisy chain control signals and PRI_SG with a simple st...

Page 18: ...23E75H53C2T00 DCM3623E36G26C2T00 DCM3623E50T0480M00 DCM3623E50T0680M00 DCM4623ED2K04A5M00 DCM4623ED2N06A9T00 DCM4623ED2H15E0T00 DCM4623ED2K31E0M00 DCM3623E36G17C2T00 DCM3623E50M04A2M00 DCM4623ED2N13C8T00 DCM4623ED2K26E0M00 DCM3623E36G06A8T00 DCM3623E50M31C2M00 DCM3623E50M53C2M00 DCM3623E75H26C2T00 DCM3623E75H40C2T00 DCM4623ED2K53E0M00 DCM3623E50M13C2M00 DCM3623E50M17C2M00 DCM3623E50T31A6M00 DCM362...

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