DAC7760: DAC7760 voltage and current output problem

furkan f

Part Number: DAC7760

i'm trying to use dac7760 with STM32f1 and this is my schematic

I use the following function to send data from STM32f1 to a DAC7760:

static HAL_StatusTypeDef WriteSingle_DAC7760(uint8_t ch_Addr, uint16_t ch_Data){     
  uint8_t liv_Data[3]; // 0: ch_Addr  1:ch_Datadata?8? 2:ch_Datadata?8?
  uint8_t liv_RXData[3] = {0};
  liv_Data[0] = ch_Addr;
  liv_Data[1] = (ch_Data & 0xff00) >> 8;
  liv_Data[2] = ch_Data & 0x00ff;
  status = HAL_SPI_TransmitReceive(&hspi2, liv_Data, liv_RXData, 3, 500); 
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_3, GPIO_PIN_SET);
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_3, GPIO_PIN_RESET);
  HAL_Delay(1);
  return status;
}

I use this initial settings for DAC7760

//Write reset register
WriteSingle_DAC7760(0x56, 0x0001);

//Write control register 1001 0000 0000 0001  
WriteSingle_DAC7760(0x55, 0x9001);

//configuration register 0000 0011 0000 0000
WriteSingle_DAC7760(0x57,0x0300);

WriteSingle_DAC7760(0x01,32000);

there is no output on current output and voltage output. Am I missing a part or did I do something wrong?

over 4 years ago

0 Kevin Duke over 4 years ago

TI__Mastermind 46290 points

Furkan,

Can you perform a read on the SPI bus to verify that the SPI register contents are as expected? Looking at the code alone can be misleading since the ultimate physical manifestation of the signals on the PCB may be different - so it is possible the writes are not being applied as expected.

0 furkan f over 4 years ago in reply to Kevin Duke

Prodigy 70 points

i use an logic analyser and when power supply turned off spi seen work well but when i turned on power supply for dac with 24V mosi output corrupt and sen just one pulse while clock data send clock pulses. i looked mosi trace but there is no problem with mosi pin trace.

0 Kevin Duke over 4 years ago in reply to furkan f

TI__Mastermind 46290 points

Hello Furkan,

I apologize for the delays but last week I was out of office on business travel. Do you have any new updates on this topic? Would you be able to share the oscilloscope capture of the MOSI transfer on the SPI bus for me to check?

0 furkan f over 4 years ago in reply to Kevin Duke

Prodigy 70 points

Thank you Duke of DACs, I changed the dac and my problem was solved.

Data converters

Data converters forum

DAC7760: DAC7760 voltage and current output problem