ADC12DJ5200RF: NCO Frequency

new2day

Expert 1950 points

Part Number: ADC12DJ5200RF

Table 7-130 says F_NCO = FREQA0 * 2³²* FADC while also says FREQA0 = 2³² * FNCO /FS.

They looks not matched between equation FREQA0 vs. F_NCO

FADC = FS, right?

what's the NCO Frequency with default FREQA0 = 0xC0000000 at Fs = 5GHz.

Thank you.

over 3 years ago

0 Neeraj Gill over 3 years ago

TI__Mastermind 20541 points

HI,

1. Yes FADC = FS.

2. FNCO = 3750MHz.

0x223 is set to 0xC0

0x222 is set to 0x00

0x221 is set to 0x00

0x220 is set to 0x00

Regards,

Neeraj

0 new2day over 3 years ago in reply to Neeraj Gill

Expert 1950 points

Hi Neeraj,

About the equation, which one is right? Thank you.

1. if F_NCO = FREQA0 * 2³²* FADC,

then, FREQA0 = F_NCO/(2³²* FADC)

2. if FREQA0 = 2³² * FNCO /FS.

then F_NCO= (Fs * FREQA0)/2³²

0 Neeraj Gill over 3 years ago in reply to new2day

TI__Mastermind 20541 points

Yes that is correct.

Regards,

Neeraj

0 new2day over 3 years ago in reply to Neeraj Gill

Expert 1950 points

Hi Neeaj,

Which one is right, 1 or 2 above.

They are not matched in Table 7-130, below,

It says F_NCO = FREQA0 * 2³²* FADC, if so, FREQA0 = F_NCO/(2³²* FADC) not as below.

It also says FREQA0 = 2³² * FNCO /FS

Thank you.

+1 Neeraj Gill over 3 years ago in reply to new2day

TI__Mastermind 20541 points

2. is correct equation.

2. if FREQA0 = 2³² * FNCO /FS.

then F_NCO= (Fs * FREQA0)/2³²

Regards,

Neeraj

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ADC12DJ5200RF: NCO Frequency