DAC61416: Voltage output problem

Prodigy 50 points

Replies: 6

Views: 90

Part Number: DAC61416

Hello:

I tried to output a voltage of 0 to 20V with DAC61416. I used MC9S12 microcontroller to communicate with DAC61416 via SPI.When I select the output range is -5 V to +5 V 、 -10 V to +10V、-20 V to +20V or -2.5 V to +2.5 V ,the output voltage is only 1.4V. When I select the output range is 0V to +5V 、 0V to +10V 、0V to +20V or 0V to +40V ,the output voltage is 0v. I am sure there is no problem with SPI communication.

This is the register configuration:

DrvDacWriteReg(DACRANGE2R_ADDR, 0x2222);
 DrvDacWriteReg(DACRANGE3R_ADDR, 0x2222);
 DrvDacWriteReg(SPICFGR_ADDR, 0x0A84);
 DrvDacWriteReg(GENCFGR_ADDR, 0x3F00);
 DrvDacWriteReg(DACPWDWNR_ADDR, 0x0000);
 DrvDacWriteReg(BRDCFGR_ADDR, 0xFFFF);
 DrvDacWriteReg(BRDCASTR_ADDR, 0xFFFF);

Please let me know why this problem occurs or if you can help me directly with this, it would be a great help.

Thanks and Regards,

chaogang zhu

6 Replies

  • Hi Chaogang Zhu,

    Can you share the schematic for your system?

    Thanks,
    Paul

  • In reply to Paul_Frost:

    Hi Paul,

    This is my schematic.

    Thanks,

    chaogang zhuAS_board_20190916.PDF

  • In reply to Paul_Frost:

    The voltage between VCC and VSS is 24V.

  • In reply to Paul_Frost:

    I would like to ask what is the influence of VCC and VSS voltage on the output voltage of DAC?

  • In reply to chaogang.zhu:

    Hi Chaogang,

    Looks like you haven't enabled the internal reference in the GENCONFIG register. The bit REF-PWDWN should be 0.

    Let me know if that resolves the issue.

    Regards,

    Uttam Sahu

    applications Engineer, Precision DAC

  • In reply to Uttam Sahu:

    Hello Uttam,

    My GENCONFIG register value is 0x3F00t,the bit REF-PWDWN is 0.

    I have found the cause of my problem.There is something wrong with my hardware design.I measured my VSS pin voltage at -15V.

    Later I tried to connect VSS to the ground.I can use the DAC to output the voltage I want.

    Thank you for your reply.

    chaogang zhu