3.2 A Chopper-Stabilized Amplifier with a Relaxed Fill-In Technique and 22.6pA Input Current

In chopper amplifiers, the interaction between the input signal and the chopper clock can cause intermodulation distortion (IMD). This is due to amplifier delay, which causes signal transitions generated by the input chopper to arrive at the amplifier's output slightly later than the corresponding clock transitions of the output chopper. This...

31.4 A Chopper-Stabilized Amplifier with -107dB IMD and 28dB Suppression of Chopper-Induced IMD

Amplifiers often employ chopping to achieve low offset and low-frequency noise. However, the interaction between the input signal and the chopper clock can cause chopper-induced intermodulation distortion (IMD) [1] -[5]. This is especially problematic for input frequencies (Fin) near even multiples of the chopping frequency (FCH), as the...

An Auto-Zero Stabilized Voltage Buffer with a Trimmed Input Current of 0.2pA

This paper presents an input-current trimming scheme for auto-zero amplifiers. Since their input current is mainly due to charge injection,the scheme operates by trimming the clock swing,and hence the charge injection,of two dummy input switches. At room temperature,the trimming scheme reduces the maximum input current of an auto-zero...

An Auto-Zero Stabilized Voltage Buffer with a Quiet Chopping Scheme and Constant Input Current

The readout of high-impedance sensors and sampled voltage references [1] requires amplifiers that can achieve both low offset and low input current. Recently, it has been shown that this unique combination can be achieved by an auto-zero (AZ) stabilized buffer [2]. However, its low-frequency noise density is surd 5 times higher than the...

A Quiet Digitally Assisted Auto-Zero-Stabilized Voltage Buffer with 0.6pA Input Current and 0.6μV Offset

The readout of high impedance sensors and sampled voltage references [1]<br/>requires amplifiers with both low offset and low input current. Chopper amplifiers<br/>can achieve low offset, but the switching of their input chopper gives rise to<br/>significant input current (40 to 110pA) [2-4]. Auto-zero (AZ) amplifiers require<br/>less input...