Power supply voltage detection circuit
US6686782B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 2002 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Mar 8, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/223
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A power supply voltage detection circuit includes a voltage division circuit for linearly dividing a power supply voltage, a reference voltage circuit for providing a reference voltage, and a comparison circuit for comparing the output voltage from the voltage division circuit and the reference voltage from the reference voltage circuit. The power supply voltage detection circuit outputs a signal upon detecting that the power supply voltage is equal to or higher than the reference voltage. A PMOS transistor is provided between the voltage division circuit and the comparison circuit. The PMOS transistor includes a source terminal connected to an output terminal of the voltage division circuit, a drain terminal connected to an input terminal of the comparison circuit, and a gate terminal connected to the ground. Until the output voltage from the comparison circuit is higher than the threshold voltage of the PMOS transistor, the PMOS transistor remains OFF, thereby canceling the input of the output voltage signal from the voltage division circuit to the comparison circuit. Thus, without using external components, the signal is prevented from being erroneously output due to the output …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.