
Ultra-low power, 1-ch integrated biopotential heart rate AFE
The device is designed to offer high performance for clinical and fitness applications, with ultra-low power for long battery life. It provides R-R intervals [broadly speaking, the beat-to-beat time] for heart rate detection.
The biopotential channel has ESD protection, EMI filtering, internal lead biasing, DC leads-off detection, ultra-low power leads-on detection during standby mode, and is equipped with extensive calibration voltages for built-in self-test. Soft power-up sequencing ensures no large transients are injected into the electrodes. The biopotential channel also has high input impedance, low noise, high CMRR, programmable gain, various low-pass and high-pass filter options, and a high-resolution analogue-to-digital converter. The biopotential channel is DC coupled, can handle large electrode voltage offsets, and has a fast recovery mode to quickly recover from overdrive conditions, such as defibrillation and electrosurgery.
The MAX30004 comes in a 28-pin TQFN or 30-bump wafer-level package (WLP), operating over the 0°C to +70°C commercial temperature range.
Next page; feature listing
Heart rate detection with interrupt feature eliminates the need to extract and process the ECG data on the microcontroller
Robust R-R detection in high motion environment at extremely low power
Clinical-grade biopotential AFE with high-resolution data converter
15.5 bits effective resolution with 5µVP-P noise
Better dry starts due to much improved real world CMRR and high input impedance
fully differential input structure with CMRR > 100dB
Offers better common-mode to differential mode conversion due to high input impedance
High input impedance > 500MΩ for extremely low common-to-differential mode conversion
Minimum signal attenuation at the input during dry start due to high electrode impedance
High DC offset range of ±650mV (1.8V, typ) allows to be used with wide variety of electrodes
High AC Dynamic range of 65mVP-P will help the AFE not saturate in the presence of motion/direct electrode hits
Longer battery life compared to competing solutions
85 µW at 1.1V supply voltage
Leads-on interrupt feature keeps µC in deep sleep mode with RTC off until valid lead condition is detected
Lead-on detect current: 0.7µA (typ)
Configurable interrupts allows the µC wake-up only on every heart beat reducing the overall system power
High-speed SPI interface
Shutdown current of 0.5µA (typ)
