Patent · US Expired

Power-on reset circuit

US6982577B2 · kind B2 · utility

4Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 30, 2004
Grant dateJan 3, 2006
Priority date
Expiry dateMar 30, 2024

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K17/223
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A power-on reset circuit is capable of outputting a normal reset signal despite slow rise of power supply voltage. A node is interposed between a MOS capacitor including a PMOS with its drain and source connected in common and an NMOS having its gate fixedly connected to a ground potential. The node is connected to a ground potential via the NMOS and also to a power supply line via the MOS capacitor. Therefore, even when the power supply voltage rises slowly after power is turned on, the potential of the node rises substantially at the same rate as the power supply voltage. After the power supply voltage reaches a predetermined power supply potential, the potential of the node is gradually lowered due to an off leakage current through the NMOS. The node is connected with an inverter operating according to the power supply voltage. When the potential of the node decreases below ½ of the power supply voltage, the reset signal outputted from the inverter goes to the H level.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.