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. 19, 2015
Filed:
Jun. 06, 2011
Applicants:
Thien Le, San Jose, CA (US);
Ping-chen Liu, Fremont, CA (US);
Inventors:
Thien Le, San Jose, CA (US);
Ping-Chen Liu, Fremont, CA (US);
Assignee:
Altera Corporation, San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F 3/20 (2006.01); H01F 38/32 (2006.01); G05F 3/16 (2006.01); G05F 3/08 (2006.01); G05F 3/04 (2006.01);
U.S. Cl.
CPC ...
H01F 38/32 (2013.01); G05F 3/16 (2013.01); G05F 3/08 (2013.01); G05F 3/04 (2013.01);
Abstract
A startup circuit to ensure a bandgap reference circuit reliably starts up or recovers from a noise disturbance is provided. The startup circuit incorporates a pull down resistor to detect the bandgap reference circuit being in a disabled state. The startup circuit creates a positive feedback loop to force the bandgap reference circuit out of a disabled state. Consequently, whenever the power supply for the bandgap reference circuit sags or if bandgap output collapses, the output of the bandgap circuit reliably ramps back up to the expected level.