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LMK61E0M: How to modify the output frequency

Roy Chou1
Genius 14465 points
Part Number: LMK61E0M

Hi Team,

We used LMK61E0M for oscillator. We would like to let output frequency equal to 185MHz and try to modify the R22/R23 register. 

But there is no output when we done the register setting. May you let me know the correct flow of register setting? Do we need another register need to set?

Roy

  • 0
    TI__Guru* 93670 points

    Hi Roy,

    What was your original configuration before you wanted to change the output frequency? R22 and R23 take care the output dividers, if you were having an output clock with a certain frequency, after the divider change, you will have output clock with a different frequency, unless you set the dividers to invalid values.

  • 0 in reply to Noel Fung
    TI__Genius 14465 points

    Hi Noel,

    We used default setting as beginning. And the output frequency is 70.6MHz as datasheet showed. Now we would like to change the frequency. Could you let me know how to change to 185MHz frequency output? 

    Regards,

    Roy 

  • 0 in reply to Roy Chou1
    TI__Guru* 93670 points

    Hi Roy,

    1. go to EZ Config

    2. change the output frequency to 185 and then click Generate Configuration button.

    3. Go back to PLL, TICS Pro has completed the configuration for 185MHz output.

  • 0 in reply to Noel Fung
    TI__Genius 14465 points

    Hi Noel,

    Thanks for information. I used TICS-Pro and followed your steps.

    Could you export the hex register values and issue the command to generate the 185MHz? Due to COVID, I couldn't do the real measurement. I may provide the register setting to customer.

    4743.HexRegisterValues.txt 
    R0	0x0010
R1	0x010B
R2	0x0200
R8	0x08B0
R9	0x0901
R16	0x1000
R17	0x1180
R20	0x1400
R21	0x1511
R22	0x1600
R23	0x1706
R24	0x1810
R25	0x1900
R26	0x1A33
R27	0x1B00
R28	0x1C00
R29	0x1D04
R30	0x1E00
R31	0x1F00
R32	0x2005
R33	0x2103
R34	0x2224
R35	0x2327
R36	0x2421
R37	0x2502
R38	0x2602
R39	0x2707
R47	0x2F00
R48	0x3000
R49	0x3110
R50	0x3200
R51	0x3300
R52	0x3400
R53	0x3500
R56	0x3800
R72	0x4802
     

    Is my understanding correct?

    Regards,

    Roy

  • 0 in reply to Roy Chou1
    TI__Guru* 93670 points

    Hi Roy,

    File --> Export hex register values.