Operational amplifier for low supply voltage applications
US5457426A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1993 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Jun 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/45076
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An operational amplifier for low supply voltage applications. The operational amplifier includes inverting and non-inverting inputs and a single-ended output. The operational amplifier also includes source transistors for pushing the output and sink transistors for pulling the output to obtain particular output voltage swing. Connections between the inputs and output include DC biasing circuitry. In low supply voltage applications, voltage drop due to transistors of amplifier circuitry can be significant and can affect possible range of output voltage swing. The DC biasing circuitry includes four identically sized n-channel transistors; three of the n-channel transistors receive a second bias current input and one of the n-channel transistors receives a first bias current input, identical to the first three identically sized n-channel cascode transistors are connected to the n-channel transistor that receives the first bias current input and to two of the n-channel transistors receiving the second bias current input; the other n-channel transistor receives the second bias current input and is connected to a correcting transistor of select size and characteristics. The correcting tr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.