AWR1642: ADC bits in AWR1642

Wesley He

Part Number: AWR1642

Hello team,

In AWR1642, we have 12 bit ADC, but we can get the 16 bit output after AFE. How did the AFE process the 12 bit ADC input to 16bit? left shift ADC data at the input of the DFE? <<4?

Thanks,

Wesley

over 6 years ago

0 Vivek Dham over 6 years ago

TI__Guru 58035 points

Hello Wesley,

Yes, the lower 4 bits are dropped.

Regards,

Vivek

0 Wesley He over 6 years ago in reply to Vivek Dham

TI__Expert 6225 points

Hello Vivek,

I'm asking how the 12bit adc input become 16bit in DFE's input.

What's the gain factor of the DFE?

Thanks.

0 Vivek Dham over 6 years ago in reply to Wesley He

TI__Guru 58035 points

Hello Wesley,

The ADC has 16bit data. To get to 12bit data the lower 4 bits are dropped.

Regards,
Vivek

0 Wesley He over 6 years ago in reply to Vivek Dham

TI__Expert 6225 points

Hello Vivek,

Thanks for your reply.

But in below post, I learn that the A2D conversion is 12 bit. The DFE make it become 16 bit. after the DFE, we can select the output bits. So can you please provide more details?

4) The Radar Sensor has 12bit A2D conversion, the DFE block after this is performed with 16bit precision. The output of the DFE is saturated and rounded to 12/14/16bits. The HSI (CSI-2 or LVDS format) is normally output in the resolution of the DFE.

Link: https://e2e.ti.com/support/sensors/f/1023/t/603675?AWR1243-general-questions-of-using-AWR1243-chipset

Thanks.

Wesley

0 Vivek Dham over 6 years ago in reply to Wesley He

TI__Guru 58035 points

Hello Wesley,

No, the ADC (along with the corresponding digital filters etc.) as such is 16bits.

Regards,

Vivek

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AWR1642: ADC bits in AWR1642