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OPT9221: opt9221 , opt8241

Part Number: OPT9221
Other Parts Discussed in Thread: OPT8241

Hi.

We are trying to develop lidar module using opt9221 and opt8241

 

Let me ask you following questions about  that.

 

1) About De-Aliasing method

 

There describes "de-aliasing" method on the datasheet. (datasheet p31 - p33)

This method is to extend the TOF range by using 2-modulation lights, I suppose.

For example, the distance is extended up to 15m by using both 70MHz and 80MHz modulation lights.

       But I would like to know the detail mechanism of de-aliasing, for example,

       How are the illumination and photo detect timing of 2 different frequency light doing?

       How is the actual calculation doing on the OPT9221?

I also think it need more current to reach object.

i want to know how to increase current on this circuit . Which part change we need in attched circuit? or plz recommend

 

 

1) Patent

 

The above "de-aliasing" method is developped by TI, isn't it?

I think TI also have patents about de-aliasing.

I am wondering that there is no problem to use this method without any patents appoval.

 

 

tks

  • You can research the web and find TOF de-aliasing. if you like to understand TI patent you can search patent office. TOF sensor based on modulatlion has a c/(2*f) max range, beyond which, phase will wrap around. Two frequencies can lead to a much lower "beat" frequency, and that extends the range. More illuminating power is needed to reduce depth noise, as the noise increases with reduced reflected amplitude.