This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LSF0108: LSF0108 application

Part Number: LSF0108

Hello Team,

My customer use LSF0108 for 1.8V translation to 3.3V, they connect VREF_A pin to a 1.8V, and connect VREF_B and EN pins to a 3.3V through a 200 kΩ resistor. I think the design is OK. For this design, what's the voltage of VREF_B and EN pins? My customer test the voltage is 2.6V, it is correct? thanks

 

Regards,

Nanfang

  • Hi Nanfang,

    The voltage at the EN/VREF_B node will be generated by the bias current from the 200kΩ resistor through the internal FET and will be specific to the device. You should see VREF_A + Vth at that node, with Vth being the FET threshold voltage, which we do not characterize for this device.

    Given this information, you can solve for Vth from the information you provided:

    Vth = VREF_B - VREF_A = 2.6V - 1.8V = 0.8V

    I would expect the threshold voltage to be between 0.5V and 1V, so this value is likely correct.  Is the device translating correctly in the configuration you have?