LEVEL SHIFTING CIRCUIT

PURPOSE:To facilitate inverting operation even when an input signal is at low level and to improve fastness and design performance by accelerating switching operation in input signal switching by 1st and 2nd current supply circuits. CONSTITUTION:When the input signal Si varies to a high level V2, a transistor (TR) 1 turns off and a TR 2 turns on. Therefore, both TRs 2 and 4 turn on. At such a time, the input signal Si is at the high level V2, so a TR 42 turns on. The output signal So at an output terminal 13, on the other hand, is still at the high level, so a TR 41 also turns on and a current flows to a TR 43. Therefore, the gate potential of the TR 4 rises and its ON resistance increases. Consequently, the potential at the output terminal 13 falls and the ON resistance of a TR 3 decreases, positive feedback is provided, so the switching operation of a level shifting circuit is accelerated.