MAX10 - 10M02DCV36I7G - BOARD - High current draw or shortcircuit ?

Hi all,

Target : MAX10 - 10M02DCV36I7G

Quartus: 15.1

We are trying to design a very minimalist and small MAX10 FPGA board using the 10M02DCV36I7G. The schematic (attached) of the board is very simple and only implement the following features :

• Single 3.3V supply power : VCCIO3_5_6 = VCCIO_1_2_8 = VCCA = VCC_ONE and are all connected to a single 3.3V LDO regulator

• We aim to implement a SPI compatible bus. Considering the small amount of IO on this chip we decided to use the JTAG Pins Sharing features

• The FPGA is clocked with a 50MHz Resonator

• And a small led is connected to one of the digital I/O

• Other IO are connected to board pins or left unconnected

the problem :

When we power the board the board draw a large amount of current (>400mA) and the voltage drops. So there must be a short-circuit somewhere but we are unable to locate it. We tried several approaches:

• Double check the schematic (cf . schematic.pdf (https://www.alteraforum.com/forum/attachment.php?attachmentid=13793&stc=1&d=1498221708)) and

• Verify FPGA schematic pin assignment using the pin table (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/dp/max-10/10m02dc.xls) and pins connections guidelines for max10. (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/dp/max-10/pcg-01018.pdf)

• We already used a very similar schematic for a 10M02 EQFP144 that have been validated with working board.

• Re-Checked pin order between our PCB Footprint and Quartus Prime Pin Planner view founding no differences. (cf. pinnout-comparison.pdf (https://www.alteraforum.com/forum/attachment.php?attachmentid=13793&stc=1&d=1498221708))

• Asked the manufacturer which sort of test they performed: Their answer “all the board passed assembly optical inspection (aoi) and solder paste inspection (spi)”. So apparently it shouldn’t be a soldering issue.

• Unsuccessful JTAG chain test with the board connected to a 450mA – 3.3V power supply.

We probably missed something and are now out of ideas...

Thanks for your help.

Tim