Patent ID: 11909567
Assignee: HITACHI, LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 5:
6. An equalization system, wherein
the equalizer according to claim 1, is mounted on a linear repeater,
a loss of a data signal transmitted by a first communication medium in the communication medium is equalized and compensated by the equalizer,
the compensated data signal is transmitted to a receiver via a second communication medium by a driver circuit of the linear repeater,
an EYE monitor provided in the receiver monitors an eye pattern based on a waveform of the received data signal and outputs an evaluation value of an opening degree of an eye pattern opening portion,
a CAL logic circuit provided in the linear repeater executes a calibration loop in which control is executed to apply a displacement amount stepwise to a value of a mutual conductance gm2 of third and fourth transistors of the equalizer, in which an evaluation value of an opening degree of the eye pattern opening portion of a data signal equalized by the equalizer at each stage is acquired from the EYE monitor, and in which a gm2 adjustment value is searched for and set at which the opening degree of the eye pattern opening portion at maximum, and
a gm2 adjustment unit mounted on the linear repeater receives a control instruction to apply the displacement amount stepwise from the CAL logic circuit to the gm2 value, and applies a voltage corresponding to a first terminal of a variable bias current source connected to second terminals of the third and fourth transistors of the equalizer according to the control instruction.