(19)
(11) EP 1 450 473 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
published in accordance with Art. 158(3) EPC

(48) Corrigendum issued on:
20.10.2004 Bulletin 2004/43

(43) Date of publication:
25.08.2004 Bulletin 2004/35

(21) Application number: 02804347.9

(22) Date of filing: 15.11.2002
(51) International Patent Classification (IPC)7: H02M 3/07
(86) International application number:
PCT/JP2002/011966
(87) International publication number:
WO 2003/049264 (12.06.2003 Gazette 2003/24)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE TR

(30) Priority: 30.11.2001 JP 2001366340

(71) Applicant: Sony Corporation
Tokyo 141-0001 (JP)

(72) Inventors:
  • Toyozawa, Noboru
    Shinagawa-ku, Tokyo 141-0001 (JP)
  • Nakajima, Yoshiharu
    Shinagawa-ku, Tokyo 141-0001 (JP)

(74) Representative: Müller, Frithjof E., Dipl.-Ing. 
Müller Hoffmann & Partner Patentanwälte Innere Wiener Strasse 17
81667 München
81667 München (DE)

   


(54) POWER GENERATION CIRCUIT, DISPLAY APPARATUS, AND CELLULAR TERMINAL APPARATUS


(57) 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).