Operational amplifier circuit with slew rate enhancement
US5343164A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1993 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Mar 25, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45248
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A low power operational amplifier adjusts its output slew rate by providing additional bias current to its differential amplifier stage when the amplitude of the differential input signal exceeds a given threshold. The additional bias current provides an enhanced current for charging or discharging an internal compensating feedback capacitor of the operational amplifier. The power dissipation of the operational amplifier is kept low by employing FET transistors for the basic operational amplifier functions and by minimally biasing the slew rate enhancement circuitry associated with monitoring the amplitude of the differential input signal as well as providing the additional current to the differential amplifier stage when the amplitude of the differential input signal exceeds the given threshold. The given threshold for the differential input signal is determined according to the bias currents and the width-to-length ratios of the FETs of the differential input stage and the FETs of the monitoring and adjustment circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.