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CDCE62005 : Change of Input from Secondary to Primary

Other Parts Discussed in Thread: CDCE62005

Hi,

I am using CDCE62005 in my board. Secondary input pins are used at input side and 50MHz LVCMOS clock is supplied to Sec input pins. The circuit is working fine with different output frequency settings. I took help from TI forum before the functioning of the circuit (https://e2e.ti.com/support/clocks/f/48/p/318410/1116156#1116156)

I attached the full settings of CDCE62005 in working condition. File name :CDCE62005_REGISTER SETTINGS for CLOCK SYNTHESIZER1_125MHz.txt

Now customer wants to use Primary input and disable secondary input pins. So we updated the Reg 1, Reg 2 and Reg 5 settings manually. The updated Register file is attached. File name : CDCE62005_Primary_Input.txt

But even though we do not connect source to Primary Input pins we are getting clock output (in the presence of Secondary Input source). Please let us know why this is happening, are we missing anything in the register setting?

Regards,

Vijetha

* REGISTERS
0	E9040300 
1	E9040321 
2	E9040302 
3	E9040323 
4	E9040314 
5	00040E85 
6	073E03E6 
7	BD9075F7 
8	20009D98 

* INPUTS
PRI	50
SEC	50 - Selected
AUX	25

* EXTERNAL COMPONENTS
C4	1
R4	1
C5	1

* Internal Loop Filter Components :
C1 = 1.5 pF
C2 = 473.5 pF
C3 = 5.5 pF
R2 = 24 KOHM
R3 = 5 KOHM

BW = 378.4 KHz

Charge Pump Current = 200 uA.

PFD Frequency = 25 MHz

VCO1 Output Frequency = 1000 MHz
VCO Gain = 40 MHz/V

* Output Frequencies :
125 MHz
125 MHz
125 MHz
125 MHz
125 MHz

REGISTERS
   Primary    |   Secondary
	 EB04032    |    E904030 
	 E904030    |    E904032 
	 E904030    |    E904030 
	 E904032    |    E904032 
	 E904033    |    E904033 
	 00040E7    |    00040E8 
	 073F03E    |    073E03E 
	 BD9075F    |    BD9075F 
	 20009D9    |    20009D9 

PORTS
0	9D
1	FF
2	DF
3	F9

INPUTS
PRI	50
SEC	0
AUX	0

EXTERNAL COMPONENTS
C4	280.4992u
R4	25.7305
C5	9.5963u