| 摘要 |
<p>A power supply generating circuit, a display apparatus incorporating the same, and a portable terminal device using the display apparatus as an output display unit are provided. In a DC-DC converter having a charge pump circuit (31), a voltage dividing circuit (32), and a regulation circuit (33), p-channel MOS transistors (Qp21, Qp22, Qp31) are turned on/off based on an enable pulse enb to make the voltage dividing circuit (32) and a comparator (41) active only for a period of regulation time and inactive otherwise. This can cause a current to flow in voltage-divider resistors (R1, R2) and the comparator (41) only for a certain period of time required for the regulation operation, thus reducing the power consumption loss caused by a constant current flow in the voltage-divider resistors (R1, R2) and the comparator (41). <IMAGE></p> |
