[54] VOLTAGE BOOSTER CIRCUIT OF THE CHARGE-PUMP TYPE WITH BOOTSTRAPPED OSCILLATOR
[75] Inventor: Christian G. Kassapian, Marseille, France
[73] Assignee: SGS-Thomson Microelectronics S.A.,
Saint Genis Pouilly, France
[21] Appl. No.: 128,871
[22] Filed: Sep. 29,1993
[30] Foreign Application Priority Data
Oct. 1, 1992 [FR] France 92 11751
[51] Int. CI.6 H03K 3/00
[52] U.S. CI 327/536; 327/258; 327/259;
327/530; 327/291; 327/295; 327/239; 327/306
[58] Field of Search 307/262, 264,
307/263, 363, 296.2, 513; 331/57, 46; 327/291, 258, 589, 596, 536, 548, 534, 535, 144, 145, 295, 259, 239, 306, 530
[56] References Cited
U.S. PATENT DOCUMENTS
4,409,496 10/1983 Baba 327/536
5,097,226 3/1992 Pascucci et al 331/57
5,202,588 4/1993 Matsuo et al 327/536
5,394,372 2/1995 Tanaka et al 327/536
The invention relates to charge-pump circuits used for the generation, in an integrated circuit, of an internal supply voltage Vpp which is considerably greater than the external supply voltage Vcc. In a charge pump configuration with capacitors and transistors, certain transistors must be driven by bootstrapped logic signals, i.e., having a logic level which is greater than Vcc in order to overcome the threshold voltage of the transistors. According to the invention, there is an oscillator followed by a phase splitter stage which is in turn followed by a bootstrap amplifier stage. The oscillator is a ring oscillator having a number of logic gates which is as small as possible, preferably only three. A satisfactory frequency stability of the charge pump is thus obtained and therefore its design is made easier and its adaptability to various electronic circuits is improved.
23 Claims, 4 Drawing Sheets
