This paper presents an integrated switched-capacitor-based low-power fully-differential analog front-end (AFE) for simultaneously detecting electrocardiogram (ECG) and respiration rate (RR). A current-driven passive mixer is used to up-convert the RR signal, and a preamplifier including a driven-ground common-mode feedback (CMFB) loop amplifies both the ECG and modulated RR signals. The modulated RR signal is then down-converted to baseband to be further amplified and detected. Switched capacitors (SCs) are widely used in the proposed AFE to provide large time constants that are also easily adjustable via the clock frequency. The chip is highly programmable, which enables complex automatic gain control (AGC) algorithms based on using a microcontroller within the loop. The AFE was fabricated in the OnSemi $$0.5\,\upmu \hbox {m}$$ 0.5 μ m CMOS process. Both simulation and measurement results verify the functionality of the chip for measuring multiple biosignals, including ECG, RR, electromyography (EMG), and galvanic skin response (GSR). Performance metrics are competitive compared to the state of the art.