ADS1299: ADS1299 Technical issues

Hi ZhongHui,

Thanks for the post. Please see my comment below. 

Q1: Please refer to Figure 39 in the datasheet for the recommended BIAS drive connection for multiple devices. 

Q2: Please refer to this E2E post for the discussion on real-time lead-off detection. 

Thanks

-TC

Hi Zhonghui,

Thanks for the patience. Please see some of my comments on the schematic.

1. Suggest having hardware control for the RESET pin for the power-up sequence (Refer to Figure 76).
2. Simplify the SPI communication of multiple devices with cascaded mode configuration (Figure 70a) or the daisy-chain configuration.
3. You can share the START and CLK pins to synchronize multiple converters, as shown in Figure 69 of the datasheet. You will only need one DRDY signal for data capture if all converters are synchronized.
4. Use only one external oscillator to provide the CLK signal to the converters instead of an individual clock oscillator for each converter.
5. The BIASREF voltage resistor may not be necessary as the device internally is capable of providing (AVDD+AVSS)/2 to the BIAS_AMP.
6. Add SPI debug test points for ADC1 and ADC2.

Thanks

-TC

Hi TCT,

Your suggestions are of great value.

Thank you for your time.

Best regards,