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.

Date of Patent:
Oct. 09, 2007

Filed:

Jul. 29, 2004
Applicant:

Adrian Finney, Oldham, GB;

Inventor:

Adrian Finney, Oldham, GB;

Assignee:

Zetex PLC, Chadderton, Oldham, GB;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G05F 3/16 (2006.01);
U.S. Cl.
CPC ...
Abstract

A temperature independent low voltage reference circuit comprises a first transistor with a threshold voltage Vth having a negative temperature coefficient. A diode having a forward voltage drop with a negative temperature coefficient coupled with its anode connected to the drain of the first transistor and its cathode connected to the gate of the first transistor. A first resistor coupled between a power supply terminal and the drain of the first transistor. A low voltage supply terminal connected to the source of the first transistor. A second resistor coupled between the gate of the first transistor and the low voltage supply terminal. The drain of the first transistor provides a voltage with a negative temperature coefficient equal to the sum of the forward voltage drop across the diode and the threshold voltage of the first transistor. A circuit providing a voltage with a positive temperature coefficient is coupled between the drain of the first transistor and the low voltage supply terminal and has an output terminal. The positive temperature coefficient balances said negative temperature coefficient so that the voltage at said output has a temperature coefficient of zero.


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