BGT24LTR22 bias currents

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radar1
Level 1
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First reply posted First question asked Welcome!

In the User's guide I am missing information about the recommended bias current settings. Which conditions need which settings? What can be a hint that an adjustment is neccessary/helpful during operation? Master Mode is currently our main focus.

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Deepa_V
Moderator
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50 likes received 250 replies posted 5 likes given

Hi @radar1 ,

There isn't exactly a recommended setting for the same but in general, the higher the current, more will be the high-temperature margin. At low temperature you won't see an effect but at high temperature, where you lose gain in the distribution network, it could happen that not all stages are saturated. This would then result in reduced TX output power and degraded RX performance. You might consider a temperature dependent biasing: reduce bias current at low temperatures to save DC current and increase the bias current at high temperature for maximum TX/RX performance.

Hope this helps!

Best Regards,

Deepa

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Deepa_V
Moderator
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50 likes received 250 replies posted 5 likes given

Hi @radar1 ,

Please use the Set_Bias_Current_Master_Mode bits from the SPI Register 10 to set the bias current values for the master mode. Do refer page 63 of AN607 for the same. 

Best Regards,

Deepa

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radar1
Level 1
Level 1
First reply posted First question asked Welcome!

Hi @Deepa_V ,

Thank you for the fast reply. But that did not answer my question above. I know how to set the bias current. This is documented. But there is nothing in the manual about my question...

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Deepa_V
Moderator
Moderator
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50 likes received 250 replies posted 5 likes given

Hi @radar1 ,

More precisely, Is it that you want to know when to choose 1mA or 2mA or as such? Or is it anything specific regarding the master mode? Can you please explain your query?

Best Regards,

Deepa

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radar1
Level 1
Level 1
First reply posted First question asked Welcome!

Hi @Deepa_V ,

yes, correct "Which conditions need which settings? What can be a hint that an adjustment is neccessary/helpful during operation?"

So what is recommended when?
Under which conditions is it better to rise/reduce?

Obviously 0mA is off, but normally 3mA?

 

Thank you! Regards!

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Deepa_V
Moderator
Moderator
Moderator
50 likes received 250 replies posted 5 likes given

Hi @radar1 ,

There isn't exactly a recommended setting for the same but in general, the higher the current, more will be the high-temperature margin. At low temperature you won't see an effect but at high temperature, where you lose gain in the distribution network, it could happen that not all stages are saturated. This would then result in reduced TX output power and degraded RX performance. You might consider a temperature dependent biasing: reduce bias current at low temperatures to save DC current and increase the bias current at high temperature for maximum TX/RX performance.

Hope this helps!

Best Regards,

Deepa

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radar1
Level 1
Level 1
First reply posted First question asked Welcome!

Yes, this answers the question, thank you! We will keep an eye on temperature vs. TX power

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