| 摘要 |
PURPOSE:To keep the potential higher than the power supply voltage in bootstrap stationarily and to use it as an external output, by providing a leakage compensation circuit to an output of a high voltage generating circuit consisting of a charge pump circuit. CONSTITUTION:An amplitude output between a power supply Vcc and ground potential is given to a node 16 in the oscillating frequency of a ring oscillator circuit, an amplitude output between a potential decreased by the threshold voltage of a transistor (TR)Q31 from the power supply Vcc and an increased potential through the capacitance coupling is given to a node 17, resulting that a voltage higher than the power supply voltage Vcc level is obtained at a high voltage generating circuit output Vpp. At a bootstrap drive circuit, when an input A is at a high voltage, a TRQ7 turns on and a node B is made to a low potential. In this case, although a current flows through a leakage compensation circuit RL connected between the high voltage generating circuit output Vpp and the node B, no remarkable drop of the output voltage Vpp is caused since no current other than a minimum current can flow. |
