If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

# DAC8775: Power Consumption on Device

Part Number: DAC8775

How to estimate the power consumption when device is at full loading? How much max. output current is able to deliver?

Vin: 12V to 15V range.

Regards

Brian W

• Hi Brian,

Joe is out of office for a few more days, so he will take a look at this when he gets back.

Thanks,

paul

• Brian,

First, the maximum output current depend on the settings of the DAC. For the current output of the DAC, the maximum output of is set by the range. For voltage outputs, you can consider the output short circuit current limit as shown in the electrical characteristics table of the datasheet. This can be set to one of several modes:

This is further described in the datasheet in the DAC Register Field Descriptions on page 51. However, I would not operate the device at the short circuit limit. There may be some affect the accuracy on the exact load output voltage because of limited load compliance. I would generally say not to go above 10mA, this is the highest current is shown for voltage output in of the characterization data shown in the datasheet.

Second, you can calculate the power consumption based on the efficiency of the output power as shown in the figures in the typical characteristics curves. For the IOUT mode, this is best shown in Figure 88, as it shows the IOUT Efficiency vs the load current. For the VOUT mode, this is best shown in Figure 95, which shows the efficiency of the VOUT mode.

If there is any question about what power is required to drive the mode, I highly recommend using the DAC8775EVM and attach the required load, and the appropriate voltage for PVDD. Then I would set the output to the maximum expected load and calculate the power from the PVDD and remove the load power being delivered to the resistors to calculate the efficiency.

Joseph Wu