CCS / DAC11001A: DAC11001A

wiotte fabrice

Part Number: DAC11001A

Tool/software: Code Composer Studio

I developed a PCB with DAC11001A but with my uC TM4C1294 I cannot load the data.
In what order should you put CLR / and LDAC with the SPI port.
cordially
Wiotte Fabrice

My Programm : VREF + =+10V and VREF- = 0V    POWER SUPLLY : VCC = +24V and VSS = 0V

ssi0PutData(0x02,0x004C80,0x03); 0x004C80 SDO enable - no alarm-DAC output update on SYNC - VREFVAL 10V -/+1.25v//
SysCtlDelay(2000);
PH1 = 0x00; // LDAC
SysCtlDelay(100);
PH1 = 0x02;

ssi0PutData(0x01,0x000000,0x03); //datas=0
SysCtlDelay(2000);
PH1 = 0x00; // LDAC
SysCtlDelay(100);
PH1 = 0x02;

//SysCtlDelay(10000);
ssi0PutData(0x01,0x7FFFF0,0x03); //datas= middle code

SysCtlDelay(2000);
PH1 = 0x00; // LDAC
SysCtlDelay(100);
PH1 = 0x02;

over 5 years ago

0 Paul_Frost over 5 years ago

TI__Guru 53773 points

Hi Wiotte,

The CLR and LDAC signals do not need to be used with every command. CLR can be held to logic HIGH at all times unless you actively want to clear the DAC output. The LDAC pulse is only needed to latch the DAC value. In this case, you would only use it when you write to the DAC output register, not the configuration registers.

You should first verify that your SPI commands are formatted correctly. I recommend you capture the SYNC, SCLK, SDIN and SDO lines during a command to verify that it matches the timing and edge requirements found in Figures 1 and 2.

Thanks,

Paul

0 wiotte fabrice over 5 years ago in reply to Paul_Frost

Prodigy 50 points

Thanks

I look the SPI data transfert un mode SPI 1 .

4 wires. Speed = 1MHz.

I have an other question.

can I really put single power for the DAC

Exemple : VCC = 24v and VSS=0V

Thanks for reply

Sorry for my english.

Cordially

Wiotte Fabrice

0 Paul_Frost over 5 years ago in reply to wiotte fabrice

TI__Guru 53773 points

Hi Wiotte,

The device requires a few other supply voltages as well: IOVDD, DVDD, & AVDD.

Thanks,

Paul

0 wiotte fabrice over 5 years ago in reply to Paul_Frost

Prodigy 50 points

Hello

yes I set IOVDD = 3.3v

AVDD = 5v and DVDD = 5v.

I will send you the screenshot of the data on port SSI0

very cordially

Wiotte Fabrice

CNRS France

0 Paul_Frost over 5 years ago in reply to wiotte fabrice

TI__Guru 53773 points

Please share your schematic as well.

Thanks,

Paul

0 wiotte fabrice over 5 years ago in reply to Paul_Frost

Prodigy 50 points

Can I reply in Private message for the schematic ?

Cordially

Wiotte Fabrice

0 Paul_Frost over 5 years ago in reply to wiotte fabrice

TI__Guru 53773 points

Yes, please email the document to frost@ti.com.

Thanks,

Paul

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CCS / DAC11001A: DAC11001A