CS1259 is a digital filter that includes an ADC signal chain, a body impedance measurement module (BIM), a Sigma delta ADC, and a digital filter. The ADC signal link includes input MUXP/MUXN and programmable low noise gain amplifier (PGA). The MUXP/MUXN has 8 input channels, including 5 external analog input channels and 3 internal input channels. After MUXP/MUXN, there is a level shift module—LVSHIFT, which can shift the input signal near the ground rail and send it to the PGA. It also has an adjustable current source IDAC1/0, which can adjust the common mode voltage of the input signal or compensate the offset voltage.
The PGA and ADC have multiple gain options, and the digital filter can be configured for multiple output rates. The human body impedance measurement module uses a sinusoidal excitation source to convert the human body impedance into a voltage signal that is transmitted to the ADC signal chain for measurement. It supports multi-electrode and multi-frequency human body impedance measurement.
Supports single-ended input
Supports multiple differential input pairs
Supports input level shift function