High speed voltage comparator with matching current sources using current difference amplifiers
US5929661A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1996 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Dec 16, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/2481
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage comparator for comparing a first input voltage to a second input voltage includes a first transistor having a gate to which the first input voltage is applied and a second transistor having a gate to which the second input voltage is applied. Third and fourth transistors, coupled to the first and second transistors respectively, each conduct a first current in response to a first reference voltage being applied to a gate of each transistor. A fifth transistor is coupled to the first and second transistors and has a gate to which a second reference voltage is applied to maintain a sum of currents conducted by the first and second transistors equal to a second current. A reference generation circuit is coupled to the third, fourth and fifth transistors and is configured to generate the first and second reference voltages having magnitudes which set the second current equal to twice the first current. A first current difference amplifier has an input coupled to the first and third transistors and is configured to generate one of a first, second and third output voltage levels in response to a sourcing, zero or sinking current, respectively, being received at its input.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.