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:
Oct. 11, 2011
Filed:
Dec. 16, 2009
Lawrence H. Edelson, Fremont, CA (US);
Michael P. Daly, Newtownmountkennedy, IE;
Trey A. Roessig, Palo Alto, CA (US);
Lawrence H. Edelson, Fremont, CA (US);
Michael P. Daly, Newtownmountkennedy, IE;
Trey A. Roessig, Palo Alto, CA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A sigma-delta converter suitable for measuring a photocurrent comprises an input node adapted to receive a current to be measured (I), a capacitor connected to the input node, a clocked comparator coupled to the input node and to a reference voltage Vat respective inputs, and a switchable current source connected to the input node which conducts a reference current Iwhen switched on. The converter is arranged in a sigma-delta configuration, with the current source switched on to pull down the voltage (V) at the input node when the comparator output toggles due to Vincreasing above V, and to be switched off when the comparator output toggles due to Vfalling below V, such that the comparator output comprises a digital bitstream which varies with I.