LSF0108:About the 200kΩ Bias Resistor Value

Takumi Furukubo

Part Number: LSF0108

Tool/software:

I am planning to use the LSF0108 for bidirectional voltage level shifting.

It will be used with Vref_A = 1.8V and Vref_B = 3.3V, but I would like to know if the 200kohm bias resistor between VCCB and Vref_B can be replaced with a 180kohm or 220kohm resistor.

Could you please explain why it is necessary to use a fixed value of 200kohm?

9 months ago

0 Jack Guan 8 months ago

TI__Mastermind 40136 points

Hi Takumi-san,

200kohm is a tested value that works- this bias resistor allows the leakage current from VREFB into VREFA to be regulated to ensure that the internals of the LSF does not become damaged and helps to regulate the V_Gate internally.

This LSF video covers this further in detail: https://training.ti.com/TLM-LSF-Bias?cu=1134826. I do not see any major issues with using a 10% deviation from the 200kohm value.

Regards,

Jack

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LSF0108:About the 200kΩ Bias Resistor Value