LOGIC CIRCUIT HAVING SUPPRESSED LEAK CURRENT TO DIFFERENTIAL CIRCUIT

摘要

A current supply control circuit controlling a current amount supplied to a differential circuit is arranged in a logic circuit. The current supply control circuit includes: a bypass route for bypassing current to the differential circuit; a switching transistor inserted into the bypass route for opening/closing the bypass route according to the signal level of the clock signal inputted from outside; and a current amount control transistor for controlling the current amount supplied to the differential circuit. The current amount control transistor adjusts the current amount according to the signal level of the clock signal. The current amount control transistor is configured so that a sufficient current amount is assured by the clock signal when current flows into the differential circuit and the current amount is limited by the clock signal when the current flows into the bypass circuit. Thus, it is possible to reduce the current amount leaking into the differential circuit when the current flows into the bypass circuit.