A good PCB layout for the MAX3002ETP+ involves keeping the analog and digital grounds separate, using a solid ground plane, and minimizing the distance between the MAX3002ETP+ and the ECG electrodes. A 4-layer PCB with a dedicated analog ground plane is recommended.
To ensure EMI immunity, use a shielded cable for the ECG electrodes, keep the MAX3002ETP+ away from high-frequency sources, and use a common-mode choke or ferrite bead on the power supply lines. Additionally, use a low-pass filter on the ECG signal lines.
The recommended power-up sequence is to first power up the analog supply (AVDD), followed by the digital supply (DVDD), and then the clock signal. This ensures that the analog circuitry is stable before the digital circuitry is enabled.
To optimize the MAX3002ETP+ for low power consumption, use the lowest possible clock frequency, disable the internal oscillator and use an external clock source, and use the power-down mode when not in use. Additionally, use a low-power microcontroller and optimize the firmware to minimize power consumption.
The recommended calibration procedure involves shorting the ECG electrodes together and adjusting the gain and offset registers to achieve a flat line on the ECG signal. Then, connect the ECG electrodes to a known signal source and adjust the gain and offset registers to achieve the desired signal amplitude and offset.
