MOS Comparator circuit
US4463270A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1980 |
| Grant date | Jul 31, 1984 |
| Priority date | — |
| Expiry date | Jul 24, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/0038
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for detecting a difference in the relative magnitudes of two voltages includes a current sensing circuit connected between the first voltage and ground to thereby cause a first current to flow in the current sensing circuit, an amplifier connected between the second voltage and ground and connected to the current sensing circuit to thereby cause a second current to flow, the second current being equal to the first current when the first voltage is equal to the second voltage, and a variable impedance inverter connected to the first voltage and connected to the amplifier, the variable impedance being controlled by the first voltage, the output of the inverter thereby being related to the difference between the first voltage and the second voltage. The invention is particularly useful for controlling a battery backup power supply in a microprocessor having a volatile memory and for creating precision delay circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.