Gen1 DCDC Converter Troubleshooting and Repair

[kiev]

The DCDC converter is a separate board in the bottom plenum of the OBC and needs a separate thread for troubleshooting and repair.

Index in post #1
Pictures in post #2
Schematics in post #3
Components and Datasheets post #4
Faults and Trouble #5->

[kiev]

Pictures here,

bottom cover of OBC removed, the DCDC is in this lower plenum, only 5 wires to CN201, 450V 20A input fuse, 125V output fuse,


DCDC board removed, MOSFETs are clamped to heatsink for cooling,


bottom side of the DCDC board, no microcontroller found,


Heat-sinked components attached to cold plate, MOSFETs, Transformer, Diode Module, Output Inductor,

[kiev]

Schematics here,

The E-03 connector to the OBC and DCDC converter


Sketch of high power component trace of the Buck Converter


Sketch of HV Input section that creates secondary supplies for startup [IC101 and IC102]


Sketch of the "DCSW", the white wire on pin 1 of CN201 [appears to be a Start or ShutDown Switch]


Pin 3, 12V Always ON; Current Sensor; PWM Error Amplifier input


Soft Start command of IC201 PWM chip related to presence of voltages (+12 pin3, output 12, +15 TP201) and output current [signal for AND gate of IC207-D pin 12] and temperature signal.


Temperature and Current Sensor Conditioning and contribution to the control of the PWM chip


Soft Start command leg for the TP201 voltage, the "15V" secondary supply created by the TR105, using the IC202 -A and -B Comparators with hysteresis switching band to filter nuisance oscillations.


The IC202 Comparator -C and -D redrawn for easier analysis of the threshold and signal paths (Output 12V) used to feed the AND gate of IC207-D pin 12
[edit]
plus found a cluster of Common Vias linking CN201 pin 6, the Switched 12V input.

[kiev]

Components and datasheets here,

The HV components have reference designators in the 100-series; the LV side components are -200 and -300 series. e.g. resistors, capacitors, transistors, ICs.

FUSE101, 450V 20A, marked "NEW"

IC209, Linear Tech LT1461DH5, LDO 5V reference, https://static6.arrow.com/aropdfconvers ... /1461f.pdf

Q229, marking code "CGRZ", 2SC5053, NPN 50V, 1A,

IC101, NEC uPC1099G, switching regulator, https://www.datasheetarchive.com/pdf/do ... rm=UPC1099

IC102, etched ?, likely an NEC uPC277 dual comparator;
https://www.renesas.com/us/en/doc/Docum ... V0DS00.pdf

IC208, NEC uPC1251 dual op amp, https://datasheetspdf.com/pdf-file/1037 ... /UPC1251/1

IC202, NEC uPC177GR, quad comparator, https://pdf1.alldatasheet.com/datasheet ... R-9LG.html

IC203, "277" NEC uPC277, dual comparator, https://www.renesas.com/us/en/doc/Docum ... V0DS00.pdf

PC101, NEC PS2703 photocoupler, https://media.digikey.com/pdf/Data%20Sh ... 2703-1.pdf

Q110, Fuji 2SK3983 N-MOSfet, 900V, 2.6A, 6.4Ω, https://americas.fujielectric.com/files/2SK3983-01L.PDF

Q109, NEC 2SC4942, NPN 600V, 1A, https://alltransistors.com/pdfdatasheet_nec/2sc4942.pdf

Q101-104 are Fuji 2SK3697 N-MOSFETs, 600V, 42A, 14mΩ, https://americas.fujielectric.com/files/2SK3697-01.PDF

Diode Module, Nihon Inter Electronics, P2H80QH20, https://www.digchip.com/datasheets/down ... =P2H80QH20

Small signal transistors identified by marking code and reference designators:
"K N", PMV48XP or Toshiba 2SJ305 P-channel FET; Q211, 212, 218, 233

"L 6", NEC 2SC1623 NPN; Q205, 207, 213, 214, 222, 223, 227, 232, 234

"S 6", seems to be PNP ; Q208, 210

"G16", seems N-mosfet; maybe IRL2502. Q203, Q111, Q219, Q220; https://alltransistors.com/pdfview.php? ... _rectifier


IC201, TI UC2825AQDW, High Speed PWM Controller (FET gate driver), https://www.ti.com/lit/ds/symlink/uc2825a-q1.pdf

IC204, IC205; VHC14, Hex Schmitt Inverter, https://media.digikey.com/pdf/Data%20Sh ... ev2006.pdf

IC207, VHC08, Quad 2-In AND gates, https://www.onsemi.com/pub/Collateral/MC74VHC08-D.PDF

CS201, LEM HC2H200-S, Hall-Effect Automotive Current Transducer, https://www.lem.com/sites/default/files ... 0clips.pdf

Transformers:
TR101, TR102, ZT0622-TRS-GD, Gate Drivers for Q101-104

TR103, Step-down Power transformer mounted to heatsink, TDK 202V0A3

TR104, ZC19A105, signal transformer for output of power transformer

TR105, CS3871A JXE SUMIDA, HV primary with 2 LV secondaries

Inductors:
L201, large flat-wire output inductor, TDK 202V0A1

[kiev]

Not Charging the 12V Aux Battery,

eldenh, Oct 2020, DTC P0A09, eldenh DCDC failure

[eldenh]

I see that I was numbering the connector terminals from the drawing, but should have been using a mirror image. With the functions in your table, the voltage checks make sense.
It seems that the DCSW and SDW are the CAN Buss communication and likely the output control lies on the board, not from the EV-ECU. So it looks like the control chip should run when powered up without HV to the FETs.
My ohmmeter checks haven't indicated anything unusual.

Elden

[kiev]

i started a separate thread for DCDC troubleshooting with pictures, schematics and datasheets. Can you do a diode check on the Mosfets, Q101-104? Also Q110.

[eldenh]

All five look OK to my vom.
Should we continue this on the other thread?

Elden

ModEdit: Previous discussion moved into this thread for completeness 27 Oct. 2020

[kiev]

Sure let's move it over to there.

@JoeS, or some other moderator; Please move this page 63 over to the Gen1 DCDC Troubleshooting thread. Thanks

ModEdit: Previous discussion moved into this thread for completeness 27 Oct. 2020

[kiev]

Moving discussions over here