Power-on reset circuit
US8519755B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 2010 |
| Grant date | Aug 27, 2013 |
| Priority date | — |
| Expiry date | Feb 25, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/223
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
When the value of a power supply voltage (VDD) becomes a first threshold value or higher, a first start-up circuit (20) causes a band gap reference circuit (10) to start a stable operation and a first voltage value (VA) is output from the band gap reference circuit (10). When the value of the power supply voltage becomes a second threshold value or higher which is greater than the first threshold, a second start-up circuit (40) turns on a PMOS transistor (MP3) of a voltage dividing circuit (30), and a second voltage value (VB) output from the voltage dividing circuit (30) becomes a value, which is derived by dividing the value of the power supply voltage according to the resistance ratio of resistors (R31, R32). From a voltage comparison circuit (50), a reset level voltage value is output when the second voltage value (VB) is smaller than the first voltage value (VA), and a power-supply voltage level voltage value is output if the second voltage value (VB) becomes the first voltage value (VA) or higher.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.