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. 20, 2018
Filed:
Apr. 12, 2017
Applicant:
Apple Inc., Cupertino, CA (US);
Inventor:
Brian D. Clark, San Jose, CA (US);
Assignee:
APPLE INC., Cupertino, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03M 1/66 (2006.01); H03M 1/06 (2006.01); H03K 5/15 (2006.01); H03H 17/02 (2006.01); H03F 3/181 (2006.01);
U.S. Cl.
CPC ...
H03M 1/0626 (2013.01); H03H 17/0248 (2013.01); H03K 5/15046 (2013.01); H03M 1/66 (2013.01); H03F 3/181 (2013.01); H03F 2200/03 (2013.01);
Abstract
A semi-digital finite impulse response, FIR, filter is configured as a sparse FIR filter and as a minimum phase lag FIR filter. The FIR filter has a delay line composed of a number of sets of delay units sequentially coupled to each other, and where some of the sets of delay units have one or more untapped delay units as part of a cascade of two or more single-sample delay units. An analog summing node is coupled to the taps and produces at its output an analog version of a digital input signal that is fed to an input of the delay line. Other embodiments are also described and claimed.