Two-channel ECG and PPG analog front end with integrated respiration and pace detection

The AFE4960P supports synchronized signal acquisition of ECG, PPG and bio-impedance signals. A PPG signal chain comprises of a current driver for LEDs and a receiver that senses the signal from PDs. The AFE can be configured as either a 2-channel ECG receiver or as a 1-channel ECG receiver and a Respiration impedance channel. The AFE signal chains can interface in a flexible manner to up to 4 electrodes. The AFE has AC and DC Lead biasing and lead on/off detection. Pacemaker pulse detection is supported on one channel. All the signal chain outputs are converted by a single ADC in well-defined time slots and stored as 24-bit words in a 128-sample FIFO which can be read out using a SPI or an I2C interface. The AFE4960P can be used to realize a 3-lead ECG system along with SpO2.