1. Field
Embodiments of the invention relate to electronic devices, and more particularly, to chopper amplifiers.
2. Description of the Related Technology
An amplifier, such as an operational amplifier or instrumentation amplifier, can include chopper circuitry for reducing the amplifier's input offset voltage. For example, in a conventional chopper amplifier, input chopping switches can be used to chop or modulate the amplifier's input signal during an input chopping operation, thereby up-shifting the frequency of the amplifier's input signal. Additionally, the amplifier can include a filter for filtering the amplifier's input offset, which can be separated in frequency from the chopped input signal. The amplifier can further include output chopping switches for demodulating or down-shifting the frequency of the chopped input signal during an output chopping operation.
Although including chopper circuitry in an amplifier can reduce the amplifier's input offset voltage, chopping can also generate ripples in the amplifier's output signal at the chopping frequency and at harmonics thereof.
There is a need for amplifiers having improved performance. Additionally, there is need for chopper amplifiers having reduced input offset voltage and reduced output voltage ripple.
USPTO Backgrounds
USPTO Backgrounds