Signal adjusting circuit and receiving end circuit using the same

A receiving end circuit, comprising:

• a transimpedance amplifier, including:
• a first signal adjusting circuit, including:
• a first amplifier including a first input terminal and a first output terminal, wherein the first input terminal receives a first input signal, and the first amplifier is configured to amplify the first input signal and output a first output signal from the first output terminal;
• a first feedback circuit, including:
• a first capacitor connected between the first input terminal and the first output terminal;
• a first variable resistor connected between the first input terminal and a first output node;
• and
• a second variable resistor connected between the first output node and the first output terminal;
• and
• a first control circuit configured to control resistance values of the first variable resistor and the second variable resistor, so as to determine a first gain of the first output signal relative to the first input signal and a second gain of a first detection signal relative to the first input signal;
• and
• a first peak detector, wherein the first peak detector is connected to the first output node to receive the first detection signal, has a first predetermined power input range, and is configured to detect a peak value of the first detection signal;
• wherein the first control circuit controls the resistance values of the first variable resistor and the second variable resistor to have a first predetermined ratio, such that the first detection signal is within the first predetermined power input range.