Simultaneous filtering and compensation circuitry and method in chopping amplifier

• Main Author: TRIFONOV DIMITAR T
• Format: Patent
• Language: English
• Published: 08.09.2009
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

A chopper-stabilized amplifier (1B) having a first output (25) includes an input chopper (9) for chopping an input signal and applying it to the input of a first amplifier (2) and an output chopper (10) for chopping an output signal of the first amplifier and applying it to the input of a switched capacitor notch filter (30-1). Notch filtering of the chopped output signal is performed by coupling a first compensation capacitor (C2) between a first output (25) of the chopper-stabilized amplifier and an output (14A) of the output chopper by means of a first switch (55) in response to a filter clock (FILTERCLK) and coupling a second compensation capacitor (C3) between the first output and an input (22A) of a second amplifier (3) by means of a second switch (58) in response to the filter clock, and coupling the first compensation capacitor between the first output and the input of the second amplifier by means of a third switch (56) in response to the complement of the filter clock and coupling the second compensation capacitor between the first output and the output (14A) of the output chopper circuit (40) by means of a fourth switch (57) in response to the complement.