DRV2667: latency between Analog input and I2C input

Hirotaka Matsumoto

Part Number: DRV2667

Hi all

Would you mind if we ask DRV2667?

We are considering the latency from input(analog or I2C) to output.
On your datasheet Figure 21. Front-End Interface P11, in case of I2C input(from RAM to Amplifier), how much is the latency?(less that 10ms or 1ms?)

There is the description "In the system application, the entire system latency must be kept to less than 30 ms total to be imperceptible to the end user".
So, we guess that it(latency) is less than 30ms at least.

Kind regards,

Hirotaka Matsumoto

over 8 years ago

0 Kelly Griffin over 8 years ago

TI__Genius 10512 points

Hi Hirotaka-san,

The start-up time is defined in the datasheet as 2ms - typical value.

0 Hirotaka Matsumoto over 8 years ago in reply to Kelly Griffin

Guru 27585 points

Kelly san

Thank you very much for your reply!

We would like to confirm one point.

In case of Analog input(from Analog input to output amplifier), how much will be the latecny?

Kind regards,

Hirotaka Matsumoto

0 Kelly Griffin over 8 years ago in reply to Hirotaka Matsumoto

TI__Genius 10512 points

Hi Hirotaka-san,

The delay time in negligible compared to the times we are talking about for the start-up time and signal chain time. There is no processing on the signal from analog input to output, so you should expect the delay time to be in the low micro-seconds or maybe nano-seconds. We have not tested this specifically.

0 Hirotaka Matsumoto over 8 years ago in reply to Kelly Griffin

Guru 27585 points

Kelly san

Thank you for your reply!

"you should expect the delay time to be in the low micro-seconds or maybe nano-seconds"
->Our customer requested us actual latency date. So, is it possible to measure actual latency?
Sorry for bothering you.
At first, could you let us know whether you can measure or not?

We appreciate your help always.

Kind regards,

Hirotaka Matsutmoto

0 Hirotaka Matsumoto over 8 years ago in reply to Hirotaka Matsumoto

Guru 27585 points

Kelly san

We are sorry to rush you, however could you give us the reply?

Kind regards,

Hirotaka Matsumoto

0 Kelly Griffin over 8 years ago in reply to Hirotaka Matsumoto

TI__Genius 10512 points

Hi Hirotaka-san,

This is difficult to measure, but I was able to run a quick test. There is no load attached to the output. I enabled a square wave on the input and the output began changing after ~1us. Of course, due to the slew rate of our device it takes about 35us to ramp to the desired output signal. Attached is an image from the test.

0 Hirotaka Matsumoto over 8 years ago in reply to Kelly Griffin

Guru 27585 points

Kelly san

Thank you very much for your cooperation!

Kind regards,

Hirotaka Matsumoto

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DRV2667: latency between Analog input and I2C input