The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 22, 2000
Filed:
May. 19, 1997
Evert Seevinck, Eersel, NL;
Monuko Du Plessis, Pretoria, ZA;
U.S. Philips Corporation, New York, NY (US);
Abstract
In a differential pair (P1, P2) actively loaded with a current mirror (N1, N2), a differential amplifier (A) drives the common terminal (Z) of the current mirror to force a zero voltage difference between the input terminal (X) and the output terminal (Y) of the current mirror. The voltage at the input terminal (X) is actively bootstrapped, via the differential amplifier (A), by the voltage of the output terminal (Y) with high precision. Thus a high voltage gain is obtained. A capacitor (CP) between the input terminal (X) and the control terminal (Z) compensates the local loop formed by the differential amplifier (A) and the input transistor (N1) of the current mirror, and forms a short circuit at high frequencies, thus reducing the active load of the differential pair to a conventional current mirror. For high frequencies the circuit has the same gain and phase properties as the standard non-bootstrapped approach and standard compensating techniques can be applied to the complete amplifier.