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1

Hi,
I have a question about the RXVGA1(mixer gain) of LMS6002D.
In “FAQ_v1.0r12.pdf”, page10 5.20, there is a formula for converting VGA1 code to dB, the formula is
G[dB] = 20*log10(127/(127-Code)), 0 <= Code <= 120.
In this formula the maximum of G is 25.174dB.
But in another document, “LMS6002Dr2-Programming and Calibration Guide-1_1r2.pdf”, Chapter “2.8 RX FE Modules Configuration”, page41.
The RFB_TIA_RXFE[6:0] has the mixer gain = 30dB if RFB_TIA_RXFE is 120(0x78).
Are these two parameters the same, or how to calculate the value in dB of rxvga1.

Thanks for your response.

2

Hello,

Actual VGA1 block maximum/variable gain is 25 dB. In the programming guide, the mixer gain is included, which is approx 5 dB over the supported frequency range.

Andrew