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DS125DF111EVM: high current and no signal detected

Part Number: DS125DF111EVM
Other Parts Discussed in Thread: DPS-DONGLE-EVM, DS125DF111

Hi, there

I got new purchased DS125DF111EVM board and the initial set up is as shown below

It was set as SMBus slave mode connected with DPS-DONGLE-EVM.

The INA+  was connected with 10Gbps PRBS data Vpp=300mV. The OUTA+ was connected to the oscilloscope.

At the beginning, when Vin=+3.3V,  current Iin is around 24-25 mA. There is no signal detected.  Could you suggest how should I set the "register" on "low level page" to make it work? or I could leave it as default?

I read the docs on , still have no clue. sorry I am very new to FPGA. 

then after a while, the current  jumped over 300 mA.  I read from data sheet that "Maximum Transient Supply Current Default Settings: CHA and CHB " can go up to 294 mA when valid input signal detected.

but still  I think the curret is too high. now even when Vin=0.1V, the curret Iin is 79 mA which is way higher than before. 

Could you please advise

1. what is the proper set up of "regieter" to detect the phase lock the 10Gbps data?

2. what is the normal operating current when Vin=3.3V?  

Thanks alot



  • Hello Jim,

    1. In order to lock to the 10 Gbps input, please ensure that the following registers on the low level page are set for the values shown in the highlighted row below:

    These register can also be set on the high level page, under the CDR tab, of the DS125DF111 SigCon profile as shown below. You can either select a standard data rate selection or manually enter the VCO frequency/ppm tolerance and then click the “write rate regs.”

    2. The normal operating current is as follows:



    Kia Rahbar