CDCE62005

Hi Li Zou,
Try to use CDCE62005 GUI to generate register values.
www.ti.com/.../scac105

Please double check 10 MHz input type (LVCMOS, LVEPCL, LVDS).
What's your output clocks frequency and type?

If the problem had not been solve, please upload schematic for TI checking.

Regards,
Shawn

Hi Shawn,

Thanks for your kind help. 

There's only SEC_REF input (10 MHz, LVCMOS) used in my design, and directly passed to all output channels.

The ini file generated from above GUI, and used in my design:

REGISTERS
0 81800220
1 81800221
2 81800202
3 EB800203
4 01800214
5 10000E85
6 040E0B66
7 BD0037F7
8 20009D98

PORTS
0 9D
1 FF
2 DF
3 F9

INPUTS
PRI 0
SEC 10
AUX 0

EXTERNAL COMPONENTS
C4 1
R4 1
C5 1

The schematic I am using is as below:

All registers are working properly with writing and reading, but,  I couldn't detect any output clock signals. Is there anything wrong with the circuit design?

I really appreciate your help!

Li

Hi Li,
The register values looks well in GUI.

The schematic capture is not clear. Please check below items.
1, Make sure each Vcc pin get correct 3.3V.
2, In case of LVCMOS input on SEC_REF+, connect pin SEC_REF- through 1 kΩ resistor to GND.
3, Make sure LVPECL output need a DC bias resistor 150 Ohm to GND on each line.
4, Make sure LVDS output has an 100 Ohm load.

Hope helpful for you.

regards,
Shawn

Hi Shawn,

Checked and modified our design per your suggestion, VCC and GND pins connect correctly, and ouput pins add a DC bias resistor 150 ohm to GND. 

If CDCE62005 EVM Board powered up, there are 1.6V on YN pins and 2.5V on YP pins, but, all YN and YP pins in my design have no DC voltage detected after powered up. In my design, VCC pins connect to 3.3 V power, and registers have no problem with write and read process. 

May I know whether we need to check the Thermal_PAD connection, or need to replace the CDCE62005 chip, or have to use the differential inputs (LVPECL, LVDS) for PRI_REF / SEC_REF? 

Thanks you very much,

Li