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:
May. 31, 2011
Filed:
Nov. 08, 2005
Lorenzo Tripodi, Eindhoven, NL;
Mihai A.t. Sanduleanu, Yorktown Heights, NY (US);
Pieter G. Blanken, Nuenen, NL;
Lorenzo Tripodi, Eindhoven, NL;
Mihai A.T. Sanduleanu, Yorktown Heights, NY (US);
Pieter G. Blanken, Nuenen, NL;
ST-Ericsson SA, Geneva, CH;
Abstract
The present invention relates to an improved PTAT current source and a respective method for generating a PTAT current. Opportune collector currents are generated and forced in two transistors exploiting the logarithmic relation between the base-emitter voltage and the collector current of a transistor. A resistor senses a voltage difference between the base-emitter voltages of the two transistors, which can have either the same or different areas. A fraction of the current flowing through the resistor is forced into a transistor collector and mirrored by an output transistor for providing an output current. By this principle an all npn-transistor PTAT current source can be provided that does not need pup transistors as in conventional PTAT current sources. The invention is generally applicable to a variety of different types of integrated circuits needing a PTAT current reference, especially in modern advanced technologies as InP and GaAs where p-type devices are not available. For example, the PTAT current source circuit of the invention can be used in radio frequency power amplifiers, in radio frequency tag circuits, in a satellite microwave front-end.