AnsweredAssumed Answered

HMC409 Bais Requirements and Start Sequence

Question asked by RF.Goddess on Apr 3, 2017
Latest reply on Apr 26, 2017 by SMcBride



Looking to use the HMC409 and have run into questions not entirely answered on the data sheet or in the Application Notes.


I will be running this device off a +5v rail. It would be ideal to run Vcc1, Vcc2, Vpd and Vbais off this rail (with proper bypassing of course)


  1.   It would be advantageous for my application to not use an active bais circuit with the HMC409.  Is it sufficient to tie the Vbais pin (pin 9) straight to the +5V with only the recommended 100 pF bypass cap, C5, shown in the application circuit?

  2.  An application note in the data sheet, "MMIC Amplifier Biasing Procedure Application Note" gives a start sequence for HBT Self-Biased Amplifier with Control Bias.  The HMC409 has both Vpd and Vbais.  

    Could a start sequence for the HMC409 device be recommended?

  3. What sequence needs to be used in order to turn off the device.
  4. A max rating is not given for Vbais, I assume it is 5V?



Much thanks for the assistance, I want to avoid damaging one of  these devices the first time I try turning it on on the bench.