AnsweredAssumed Answered

AD9122 PLL is unlock.

Question asked by JeonKihyeon on Jul 5, 2013
Latest reply on Jul 8, 2013 by Tguy

Hi,

 

I'm using the ad9122.

But i don't know whether the lock or unlock pll.

 

my device use the 150MHz REF CLK.

And setting the 0x08, 0x0A, 0x0C, 0x0D register like below.

 

0x08 : 0x5F        (For using REFCLK.)

0x0A : 0x80        (PLL Enable)

0x0C : 0x1F        (Widest bandwidth, Highest current)

0x0D : 0x92        (N1 = 8, for Fdacclk = 1.2G)

                           (N2 = 1, for Fvco = 1.2G)

 

And i read 0x06 register after setting.

But 0x06 register value is 0x08.

I think that between bit7 and bit6 must be different.

If unlocked PLL, bit7 is set and bit6 is clear.

or locked PLL, bit7 is clear and bit 6 is set.

 

The reading and writing of registers are normal.

 

I do not know what the problem is.

Wait for your advice.

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