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DAC38RF82: output issue

Cherry Zhou
Mastermind 22235 points
Part Number: DAC38RF82
Other Parts Discussed in Thread: TEST2

Hi team,

DAC38RF82 with mode LMFSHD=81180 is being used and the configuration is as below. The JESD204B LINK is ok, but there is no output when trying to give the data. The input clock is 562.5MHz, and the Sample Rate is 9 GSPS. 

wr_da 0x00f863
wr_da 0x007863
wr_da 0x013080
rd_da 0xff10000
wr_da 0x007863
wr_da 0x090003
wr_da 0x2f0000
wr_da 0x300000
wr_da 0x0a0010
wr_da 0x0c2402
wr_da 0x0d0001
wr_da 0x190001
wr_da 0x090003
wr_da 0x253100

wr_da 0x272020
wr_da 0x280330
wr_da 0x280330
wr_da 0x090003
wr_da 0x4aff03
wr_da 0x5f0123
wr_da 0x604567
wr_da 0x090003
wr_da 0x4b1300
wr_da 0x4c1307
wr_da 0x4d0007
wr_da 0x4e0727
wr_da 0x4f1c60
wr_da 0x5100ff
wr_da 0x090004
wr_da 0x0b0004
wr_da 0x0c2502
wr_da 0x241001
wr_da 0x320708
wr_da 0x310b08
wr_da 0x310408
wr_da 0x33c730
wr_da 0x090000
rd_da 0x860000
wr_da 0x090004
wr_da 0x3b0000
wr_da 0x3c8029
wr_da 0x1b0100
wr_da 0x3e0909

wr_da 0x0df000
wr_da 0x090003
wr_da 0x240000
wr_da 0x5c0000
wr_da 0x090004
wr_da 0x0df000
wr_da 0x0ae802
wr_da 0x090004
wr_da 0x0a6802
wr_da 0x090000
wr_da 0x007863
wr_da 0x090003
wr_da 0x240020
wr_da 0x090003
wr_da 0x5c0003
wr_da 0x090000
wr_da 0x007862
wr_da 0x090000
wr_da 0x040000
wr_da 0x050000
wr_da 0x090003
wr_da 0x640000
wr_da 0x650000
wr_da 0x660000
wr_da 0x670000
wr_da 0x680000
wr_da 0x690000
wr_da 0x6a0000
wr_da 0x6b0000
wr_da 0x6c0000
wr_da 0x6d0000
wr_da 0x090003
rd_da 0xe40000

Could you help check is there anything need to be taken care of? Thanks.

Best Regards,

Cherry

  • 0
    TI__Mastermind 39050 points

    Hi Cherry,

    Can you please let us know if you are using the DAC EVM or your own board design?

    Thanks,

    Rob

  • 0 in reply to Rob Reeder
    TI__Mastermind 22235 points

    Hi Rob,

    Thank you for the support.

    Rob Reeder said:
    or your own board design?

    That's my own board.

    Thanks and regards,

    Cherry

  • 0 in reply to Cherry Zhou
    TI__Mastermind 23760 points

    Hi Cherry,

    I'll try to take a look at this in the next day or so. In the meantime, can you have the customer try to place the DAC into constant input mode and set the NCO to some output frequency? You can have them write to register 0x2F (SPIDAC_TEST1) value 0x01 to place the DAC into constant input mode. The JESD data will be replaced with a constant value found in 0x30 (SPIDAC_TEST2). Mixing a constant signal (DC) with any sinusoid provides an output at the sinusoid's frequency. This means the word they place into the NCO should be showing at the output of the DAC.

    Thanks

  • 0 in reply to Chase W
    TI__Mastermind 23760 points

    Hi Cherry,

    Is there any update from the customer's side? 

    Thanks, Chase

  • 0 in reply to Chase W
    TI__Mastermind 23760 points

    Hi Cherry,

    Additionally, can you explain the format of the initial registers provided? Is this 8 bit address and 16 bit data?

    I cannot get the link up using the customer's configuration. Please provide the customer with both of these files below to try. First please have them run the default_configuration.cfg file prior to loading their configuration to see if the output becomes present. If this does not resolve, please have the customer try the second configuration titled 562p5M_J4_9GSPS_8118.cfg. Note that the PLL on their DAC IC may require a different PLL value than what my DAC IC needs due to process variation.

    Thanks, Chase