DAC8822 update rate

Hello Ryuji,

1. This timing diagram is for one time conversion. Is my understanding of update rate in attachment correct?
   1. This is correct assuming you are combining the LDAC and !WR pins together or if LDAC is permanently tied high. Otherwise, the LDAC minimum pulse width must also be included in the calculation. 
   2. Additionally, this is making the assumption that you require that the DAC output is settled to 0.0015% FSR, or 1 LSB, and that the output is transitioning from zero-scale to full-scale. For cases that the output is transitioning over a smaller code range the output will settle faster. The value you have calculated is a good worst case figure for the longest it will take for you to write a value to the DAC and for the output to fully settle. 
2. Please let me know update rate when DAC8822 convert continuously. Is it same with one time conversion? We make any stable time for DAC8822?
   1. You should be able to write to the DAC as quickly as the digital interface allows. Based on the timing diagrams this is 50MSPS. Of course, in this case the output does not ever fully settle. In your case where you are waiting for the full-scale settling time before writing another update, your calculation in your attachment holds true.

Let me know if you have anymore questions.

Asaka-san,

Your understanding is correct.

Please let me know if there is anything else I can help you with.