DAC8162: Is the DAC output held while sending a refresh command?

Hi Shinichi-san,

The software reset command initiates a power on reset. The DAC output will be reset to zero-scale (0V) after the power on reset command. 

There should not be a need to refresh any settings. If there is a concern the customer can just periodically rewrite the settings to any registers. In that case the DAC output will not change unless you are changing the reference settings or DAC output code to a different value than previous. 

Best,

Katlynne Jones

Hi Katlynne,

I talked with the customer and he has additional questions.

Could you please advise?

ｰｰｰ

Of refresh commands (1), (2), and (3), I decided to remove (1) power-on reset because it is not appropriate.

After the DAC8162 starts up normally and the Power-down command is written due to noise, I would like to send a refresh command to restore the original operation.

I am confusing because Table 5. and Table 17. have different descriptions of what happens when the Power-up command is issued.

I would like to make sure, so could you please answer the following questions?

(a) Table 5. It says that it becomes the default after the Power up command.
Which registers are affected?
Will DB0 in Table 8 be 0 or 1? Or is it a different register?
Is DAC DATA retained? Or do I need to write a new one?

(b) On the other hand, there is no mention of default in Table 17. It's just a power up. In Table 5., it is written as default. Which is correct?

I think that when it is simply powered up, the output stage in Figure 92. just returns to output (Amp-Vout switch ON, resistor network switch OFF).

If so, I believe that the original DAC DATA will be output when the Power Up command is sent. Does it match?

ｰｰｰ

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Katlynne,

Thank you for your reply.

I understand.

The Power-up command operates differently depending on whether it is reset or not.

In addition, power-on reset(H/W)  is also considered.
We also asked them to check the POR specifications (8.3.3.3 Power-On Reset (POR) Levels).

When the customer has an additional question, I consult you again.

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Shinichi-san,

Of course. Please reach out if they need further clarification or have more questions. 

Best,

Katlynne 

Hi Katlynne,

Thank you for your reply.

I tried to close this matter with your suggestion and my knowledge, unfortunately the customer could not understand yet.

I would like you to respond according to the inquiries from the customer below.

ｰｰｰThe customer's question

Please check Q1 and Q2 below.
(Please answer according to Q1 and Q2)

●Sequence image
①Reset DAC-A and DAC-B input register and update all DACs
②Enable internal reference and reset DACs to gain = 2
③Gain: DAC-B gain = 1, DAC-A gain = 1 (power-on default)
④Write to DAC-A input register ￢
⑤Write to DAC-B input register ｜
⑥Write to DAC-A input register ｜ Section (A)
⑦Write to DAC-B input register ｜
⑧Write to DAC-A input register ｜
⑨Write to DAC-B input register ｜
・ 　　　　　　　　　｜
　　　　　　　　　　　　(Repeat ⑧⑨ from then on)
・ 　　　　　　　　　｜
・ 　　　　　　　　　　　　

●(Q1) If an unintended command (Power down DAC-B; 100 kΩ to GND) is sent during section (A), which of the following commands will be used to restore the output? ?　
>>Please answer using (a), (b), (c), and (d).
If the answer is (d), please also teach me that command.)

(a) Reset DAC-A and DAC-B input register and update all DACs
Enable internal reference and reset DACs to gain = 2
Gain: DAC-B gain = 1, DAC-A gain = 1 (power-on default)
3 commands required
(b) Enable internal reference and reset DACs to gain = 2
Gain: 2 commands are required: DAC-B gain = 1, DAC-A gain = 1 (power-on default)
(c) Gain: Only the command DAC-B gain = 1, DAC-A gain = 1 (power-on default) is required.
(d) Commands other than those listed in (a) to (c) above are required.

●(Q2) Is it correct to understand that if normal operation is performed during period (A) and the command answered in Q1 is sent, the output will be maintained (no instantaneous power outage)?
>>Please answer based on the behavior when the command you answered in Q1 is sent (momentary stoppage/no instantaneous interruption).
(Example) If the answer to Q1 is (b)
①Write to DAC-A input register
②Write to DAC-B input register
③Enable internal reference and reset DACs to gain = 2 ← Q1 command transmission
　　
④Gain: DAC-B gain = 1, DAC-A gain = 1 (power-on default) ←Q1 command transmission
⑤Write to DAC-A input register
⑥Write to DAC-B input register
While commands ③ and ④ are being executed, the output value set in commands ① and ② is maintained (no instantaneous power outage).

---

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Katlynne,

Thank you for your reply.

Exactly!

I hope that your answer will help the customer understand.

I'll share your suggestion with the customer.

When the customer has an additional question, I consult you again.

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Katlynne,

I sent your answer to the customer. 

They would like  you to make sure their understanding.

Could you please see below?

（１）There are two workarounds when an unintended command (in this case: (Power down DAC-B; 100 kΩ to GND) is sent).
When the software sends the second option of Q1, "Power up DAC-B", the DAC8162 can be restored with just this command.

（２）During normal operation (normal operation = operation that repeatedly updates the registers of DAC-A and DAC-B), even if the "Power up DAC-B" command is sent, the output does not change (the previous register is (holds the output value of the value).

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Katlynne,

The customer seemed to understand your answer.

Thank you for your dedicated support.

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Shinichi-san, 

Great to hear!

Best,

Katlynne