Other Parts Discussed in Thread: DS110RT410,
Hi,
I was looking to find out about the capabilities of this device and whether the PRBS geenrator in free-running mode running from the VCO without an input can be tuned to output 10.3125G or 9.6G.
I had read through the datasheet for the this device and another similar device "DS110RT410".
From what I get from section 7.5.12 the following is true between both devices.
Both are almost identical but with different values for certain register settings after enabling the channel and disabling the charge pump for PLL. These registers are:
- Enable the VCO divider override by writing a 1 to bit 2 of register 0x09 to
- Setting the VCO divider ratio by writing to register 0x18. For output of approx 10.3125GHz set divider ratio to 1 by writing 0x0.
- Enable VCO CAP DAC divider override by writing a 1 to bit 7 of register 0x09.
- Write the desired VCO cap count to register 0x08 bit 4:0.
- DS100RT410 VCO Cap count should be set to 0x0c to yield an output VCO frequency of approximately 10.3125GHz.
- DS110RT410 VCO Cap count should be set to 0x08 to yield an output VCO frequency of approximately 10.3125GHz.
- Enable the VCO LPF DAC which can generate a VCO voltage interally by writing a 1 to bit 6 of register 0x09.
- Write the desired value of the LPF DAC output in regitser 0x1f, bits 4:0.
- DS100RT410 For output VCO frequency of approximately 10.3125GHz LPF DAC should be set to 0x12
- DS110RT410 For output VCO frequency of approximately 10.3125GHz LPF DAC should be set to 0x12
- VCO frequency in free-run will vary somewhat from part to part.
- To determine exact values of the CAP DAC and LPF DAC settings it will be necessary to directly measure the VCO frequency using some sort of frequency measurement device such as a frequency counter or a spectrum analyzer.
- When in free run mode you can use the VCO I-clock(in-phase clock) to be output. You can measure the frequency of the VCO I-clock while adjusting the CAP DAC and LPF DAC values until the VCO _-clock frequency is acceptable for your application. Then once again select the PRBS generator as the output using the output multiplexer selection field.
So I mainly wanted to find out if it's possible to run device DS100RT410 at either 10.3125G or 9.6G depending on how the frequency is tuned/calibrated (using VCO CAP count and VCO LPF DAC values)? Or if I want to run it at 9.6G if I need to use the DS110RT410?
Best regards,
Sean Suttie.
