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What are output channel currents of HMC745,HMC851 and HMC940?


My customer is considering to use HMC745LC3,HMC851LC3C and HMC940LC4B devices in their ATE system.

And they have some questions about specifications of these devices.

Below is a question among their questions that they want to confirm first.

Would you let me know the output channel current values of HMC745LC3,HMC851LC3C and HMC940LC4B devices?

(Your data sheets of these devices have a power supply current value only.)

Anyway they want to know the value of FOB & XOR Output Channel Current.

(HMC745 & HMC851 are XOR and HMC940 is FOB.)

Please let me know.



  • Hi Se-woong,

    All of these devices have CML output interface, meaning that they will be swinging 400mV on single ended 50ohms or 800 mV on differential 100ohms. In each single ended branch, ~8mA should be passing through.

    Additionally, output level adjustment pins in these ICs' output stage changes the peak to peak swing. The current passing through changes respectively.


    Sinan Alemdar

  • Hi!

    I have one more question.

    What is Current Range Spec. of each Peak to Peak Swing Level?

    I also would like to know current limit of each 1000mV and 1500mV at the condition of Single ended 50ohm.

    * HMC Output Amplitude (Single-peak to peak)

    1) 1000mV : Current ?

    2) 1500mV : Current ?

  • Hi GabeAhn,

    These parts can achieve approximately 1300mV peak to peak swing on differential output. Single ended can be achieve ~650mV at most. These swings are defined for 50ohms interface so 13mA(650mV/50ohms) would be flowing through the 50ohms load. This is achieved by changing the voltage on the VR pin. 

    Best Regards