Class B amplifier with process variation independent deadband
US7161431B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 5, 2004 |
| Grant date | Jan 9, 2007 |
| Priority date | — |
| Expiry date | Mar 2, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/45183
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A class B amplifier circuit produces a deadband that is independent of semiconductor process variations and creates a positive voltage when a differential input voltage is non-zero. A differential input amplifier couples differential currents representing the differential input voltage to a logarithmic compression circuit, which in turn creates an output voltage that is a function of the differential input voltage and is independent of semiconductor process variations. Transistor devices in the differential amplifier and the logarithmic compression circuit are biased in the non-saturated region of a transistor transfer curve in a weak inversion state. A combination of two comparator circuits compares the output voltage to a reference voltage to create a combined output voltage that is a positive when the input is non-zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.