DAC8760: Current setting problem

WU YISYUAN

Part Number: DAC8760

HI,

I have some question in setting DAC8760 as below:

Dac8760 sets the output current of 4 ~ 20mA and the actual output current of 9 ~ 12mA.

The register configuration has been confirmed to be OK by reading the register.

Do you need to do other configuration on the software? Is there a problem with the hardware design?

Code:

Dac8760 ﹐ write (w ﹐ addr ﹐ reset, 1); / / reset all registers

Dac8760 write (W addr Ctrl, (1 < < 12) | 0x05); / / configure output current

Dac8760 ﹣ write (w ﹣ addr ﹣ data, 0xFFFF); / / output 20mA

Schematic as below:

thanks,

over 6 years ago

0 Reza Abdullah over 6 years ago

TI__Intellectual 1570 points

Hello,

To understand the problem further, I'd like to know the state of the device after initial power up and reset. Can you please respond to the questions below.

1. Is AVDD voltage 5V as shown in the schematic? AVDD for this part should be between 10V and 36V. At 5V AVDD, the device will not initialize correctly.

2. What is the AVDD current at start up? It should be approximately 2-3 mA.

3. What is the REFOUT voltage after power up? It should be approx 5V.

If all 3 above conditions are confirmed to be okay, then the DAC should respond to the code written to the data register. However, to drive a 470ohm load resistor

AVDD needs to be 12V or higher to ensure that the loop compliance voltage of the current output is satisfied.

Regards,

Reza

0 Reza Abdullah over 6 years ago in reply to Reza Abdullah

TI__Intellectual 1570 points

Hello,

Were you able to try out my suggestions? Did the issue get resolved?

Regards,

Reza

0 user6222564 over 5 years ago in reply to Reza Abdullah

Prodigy 40 points

Problem has been solved

AVDD changed to 12V

Thanks

0 Reza Abdullah over 5 years ago in reply to user6222564

TI__Intellectual 1570 points

Thanks for the update. Can you please close the thread?

Regards,

Reza

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DAC8760: Current setting problem