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Altera_Forum's avatar
Altera_Forum
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14 years ago

Gain control using fpga

Hi, i have four FIR filters and i want to control the gain in the output of each filter and then sum their outputs. The result is sended to an DAC. it is possible to control the gain in fpga...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Hi Dave,

thank you again for your replay. I'm considering everything you say.

For now i need help in the follwing:

supose i have a 14 bit DAC whit 1 Vp full scale. Maping the voltagein a 14 14 bit signed representation a have that 8191~=1V and -8192 = -1 V. suppose that my original signal has gain A and a i need to increase/decrese the gain by 1 dB (1.1220 V). How could i represent this number (1.1220) in the 14 bit fixed point representation considering that my range is from 1 to -1? Is that make any sense for you? If not, just help me on implemeting a system with gain control.

thanks.