Operational track-and-hold amplifier
US5130572A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 1990 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Dec 26, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/083
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A track-and-hold circuit that consists of an operational amplifer wherein the same capacitors are used for phase compensation and as differential holding capacitors. The circuit is switched from track to hold by turning off the input stage by reverse biasing base-emitter junctions through current steering in combination with resistor clamping. Low impedance during the hold mode is maintained because one half of the differential compensation path is connected to the output. Feed-through is eliminated by cascoding the first stage and turning off the cascode devices through current steering with resistor clamping during the holding mode. The holding capacitors' droop due to bias currents is minimized by current cancellation of the second stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.