Patent ID: 8064779

Claim:
A receiving apparatus for performing reception processing on a signal transmitted in packets, the receiving apparatus comprising: a peak voltage detection circuit to detect a peak voltage of the signal; a bottom voltage detection circuit to detect a bottom voltage of the signal; a stop control circuit to generate a stop signal for stopping the operation to detect the peak voltage and the operation to detect the bottom voltage; and a threshold value output circuit to specify a threshold voltage derived from the peak voltage and the bottom voltage; wherein the peak voltage detection circuit stops the operation to detect the peak voltage at reception of the stop signal, and retains the peak voltage of a preamble of the signal detected before the reception of the stop signal; the bottom voltage detection circuit stops the operation to detect the bottom voltage at reception of the stop signal, and retains the bottom voltage of a preamble of the signal detected before the reception of the stop signal; and the threshold value output circuit specifies that the threshold voltage derived from the peak voltage and the bottom voltage is kept constant while the signal is being received; (a) wherein the peak voltage detection circuit includes: a first transistor which passes the signal; and a first capacitor which is charged to hold the peak voltage; and when the peak voltage detection circuit receives the stop signal, a gate voltage of the first transistor is changed to suppress a leak current from occurring in the first transistor based on a voltage of the stop signal and a voltage of an input-side terminal of the first transistor, causing the peak voltage of the preamble of the signal detected before the reception of the stop signal to be retained; and (b) wherein the bottom voltage detection circuit includes: a second transistor which passes the signal; a second capacitor which is charged to hold the bottom voltage; and when the bottom voltage detection circuit receives the stop signal, a gate voltage of the second transistor is changed to suppress a leak current from occurring in the second transistor based on a voltage of the stop signal and a voltage of an input-side terminal of the second transistor, causing the bottom voltage of the preamble of the signal detected before the reception of the stop signal to be retained.