Switching power supply device and a semiconductor integrated circuit
US7514908B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2005 |
| Grant date | Apr 7, 2009 |
| Priority date | — |
| Expiry date | Nov 26, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low. In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal, the boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other such that when the MOSFET is made to assume an OFF state, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.