Electric signal transmission apparatus

An electric signal transmission apparatus having a transmitter transmitting a transmission signal, a transmission path transmitting the signal transmitted from the transmitter, and a receiver receiving the signal transmitted via the transmission path,

• wherein the receiver has a decision feedback equalizer, and
• the decision feedback equalizer has an adder that receives a reception signal and adds taps of filters to the reception signal, a comparator that determines the positive/negative of an output of the adder and outputs a determination result, a shift register that delays an output of the comparator by the integral multiple of a cycle of an input clock, a reference circuit that switches a reference value of an output according to an input control signal, digital-to-analog converters that execute digital-to-analog conversion on tap coefficients of the filters, multipliers that output the taps of the filters obtained by multiplying outputs of the digital-to-analog converters and an output of the shift register to the adder, a filter coefficient adjuster that receives the output of the adder, the output of the comparator, and the output of the shift register, outputs the tap coefficients of the filters to the digital-to-analog converters, and adjusts the tap coefficients of the filters by a feedback loop, and an average peak value determiner that receives the output of the adder and a threshold value set by a program, outputs a determination result as a control signal to the reference circuit, detects an average peak value of the output of the adder, compares a magnitude relation of the detected average peak value and the threshold value, increases the reference value of the output of the reference circuit from an initial value set by the program and causes resolutions of the digital-to-analog converters to become coarse from the initial value, when the average peak value is larger than the threshold value, and decreases the reference value of the output of the reference circuit from the initial value set by the program and causes the resolutions of the digital-to-analog converters to become fine from the initial value, when the average peak value is smaller than the threshold value.