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I want to use the HMC920 for the HMC7357

Do you have an application note that discusses how to increase the output current of the HMC920 in order to use the controller with higher power devices like the HMC7357?

Thanks

Sampie

Parents
  • Hi Sampie,

    You can use multiple number of HMC920s to increase the Idrain capability. HMC920 is rated up to 500 mA. HMC7357`s default bias configuration requires 1.2A, so you will need 3x HMC920s.

    You can also bias HMC7357, by using HMC980, which can deliver 1.2A for HMC7357.

    Attached sch shows using multiple number of bias controller to increase the drain output current capability. The bias controller used on the attached SCH is HMC980, and this circuit is tested and used by us and by our customers. Same idea can be used for HMC920.

    Best,

    Kagan

    reference_appscircuit_HMC980LP4Efor2.4A.pdf
Reply
  • Hi Sampie,

    You can use multiple number of HMC920s to increase the Idrain capability. HMC920 is rated up to 500 mA. HMC7357`s default bias configuration requires 1.2A, so you will need 3x HMC920s.

    You can also bias HMC7357, by using HMC980, which can deliver 1.2A for HMC7357.

    Attached sch shows using multiple number of bias controller to increase the drain output current capability. The bias controller used on the attached SCH is HMC980, and this circuit is tested and used by us and by our customers. Same idea can be used for HMC920.

    Best,

    Kagan

    reference_appscircuit_HMC980LP4Efor2.4A.pdf
Children
  • PDF

    Hi  Kagan:

             I  use   HMC980  to   BIAS   HMC7357, here   is    the   SCH ,refer   to    your   SCH. But  there   is   a   strange   phenomenon: After  power on   2~3s,HMC7357   has  a    about 20db  Gain,continues   about  10s   then the  signal   disappeared。 What‘s   the   most probable cause  can   it  be? Is  my  SCH  right? Thanks   a   lot。

    Best,

    Kaka

  • Hi Kaka,

    When you say the signal disappears do you mean the part stops functioning entirely? How does the DC look while this is happening? Could you tell me your bias sequencing?

    Also, the schematic seems reasonable but since this inquiry was asked we have developed a calculator to select discrete components. I would suggest going over your circuit with this to ensure that the values are correct.

    https://wiki.analog.com/resources/eval/user-guides/active-bias-controllers/hmc980?s[]=hmc980

    Thanks,

    DanO