The AFE provides a single biopotential channel that measures R wave-to-R wave interval of heart beats to determine heart rate. The biopotential channel features electrostatic discharge (ESD) protection, electromagnetic interference (EMI) filtering, and DC leads-off detection.
The device offers extensive calibration voltages for built-in self-testing, and its soft power-up sequencing ensures that no large transient signals are injected into the electrodes.
A fully differential input structure features high common-mode rejection ratio (CMRR) of more than 100dB and a high impedance of more than 500MOhms, which results in improved low common-to-differential mode conversion.
A 0.7 mA leads-on feature keeps the AFE’s microcontroller in deep sleep mode, with the real-time clock in the off position until a valid lead condition is detected.
Configurable interrupts allow the microcontroller to wake up only on every heartbeat, reducing overall system power consumption.
The MAX30004 has a high DC offset range of ±650 mV (1.8 V typical) that allows it to be used with a wide variety of electrodes. The device offers ultra-low power consumption of just 85 mW at a 1.1 V supply, leading to longer battery lifetimes.
