US 7,321,261 B2
Full swing amplifying circuit and applications thereof
Matthew D. Felder, Austin, Tex. (US)
Assigned to Sigmatel, Inc., Austin, Tex. (US)
Filed on Apr. 11, 2006, as Appl. No. 11/402,189.
Prior Publication US 2007/0236285 A1, Oct. 11, 2007
Int. Cl. H03F 1/02 (2006.01)
U.S. Cl. 330—9  [327/124] 14 Claims
OG exemplary drawing
 
1. An amplifying circuit comprises:
an input chopping circuit operably coupled to chop an input signal at a chopping rate to produce a chopped input signal;
an amplifier having a first input transistor section, a second input transistor section, and a transistor load section, wherein the first and second input transistor sections are operably coupled to receive the chopped input signal, wherein the first input transistor section amplifies the chopped input signal when the chopped input signal is in first signal level range, the second input transistor section amplifies the chopped input signal when the chopped input signal is in a second signal level range, and the first and second input transistor sections amplify the chopped input signal when the chopped input signal is in a third signal level range, wherein the transistor load section is coupled to the first and second input transistors sections to produce an amplified chopped signal; and
an output chopping circuit operably coupled to chop the amplified chopped signal at the chopping rate to produce an amplified signal.