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ONET1130EC: ONET Bias Tee configuration

Part Number: ONET1130EC


can I get application notes about right EA Bias configuration?

It's not fully clearly what frequency range applied into this point of scheme (input of TOSA). We don't sure it should be 9-11 GHz or 4-6 Ghz.  As result we can't calculate filter correctly.

We need some recommendations about filter implementation for this device.

Best regards

1 Reply

  • Hi Vladimir,

    The EA Bias is the voltage bias that is required to drive the EML-modulator inside the TOSA. It is typically around -0.7V, but can be anywhere between -0.3V to -1.1V or even lower, depending on the Voltage-Power response characteristics of the modulator inside the TOSA being used. 

    A bias-T from VCC to the TXOUT+ pin is required to supply sufficient headroom voltage for the output driver transistors. It is recommended that the inductance in the bias-T have low DC resistance to limit the DC voltage drop and maximize the voltage supplied to the TXOUT+ pin. If the voltage on this pins drops below approximately 2.1V then the output rise and fall times can be adversely affected.

    The complete schematics of the design around this bias-T and the other pins is given along with the corresponding passive component recommendations (in BOM) in the EVM User guide that can be found online at: