• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 203 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS1298: error budget for ADS

jason li
Prodigy 185 points
Part Number: ADS1298

i would like to learn the application of ADS1298 to be used in physiological measurement application.  (for instance:  ECG, respiration, pacer).  i will appreciate if you share with me my following inquiring: 

1) create error budget allocation model based on the data sheet of the device (ADS1298) including measurement errors due following modules: 

multiplexer

sample and hold amplifier

converter 

i am looking for error analysis on ADS1298 similar to the link below including the factor affecting the drifting error such as integral nonlinearity, gain stability, offset stability, output range

www.dataforth.com/ic-op-amp-errors.aspx

2)  i would like to learn how to retrieve the sensitivity of signal amplitude to frequency response from the data sheet. for example, 

how to retrieve the frequency response performance based on the datasheet?  (for instance, if i inject sine wave : 1 mV input amplitude at 0.67 Hz, 5 Hz, 40 Hz, where can i find the characteristic data (the amplitude change expectation) from datasheet?)

3) how can I retrieve the noise performance at operation temperature range(0~40C), (The signal noise caused by the ECG amplifier shall be <= xx µVpp for a period of 10s. Notch filter to be turned off) 

4) how to retrieve input impedance expectation from data sheet ?  (The input impedance shall be at least xx MΩ within a DC offset voltage range of +/-300mV). 

5) how to retrieve multichannel talk expectation from datasheet?: (When an input signal limited in amplitude and rate as per iec60601-2-27: 201.12.1.101.2 is applied to selected LEAD of the multi-channel ME EQUIPMENT, with all other LEAD WIRES connected to the N (RL) LEAD WIRE, the unwante5d output in the unused LEADS shall not be greater than x % of the applied input signal.) 

  • 0
    TI__Mastermind 19815 points

    Hi,

    1) Most info TI is allowed to disclosed and shared in the public are already disclosed in the ADS1298(R) datasheet -

    https://www.ti.com/lit/ds/symlink/ads1298r.pdf?ts=1671985957978&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FADS1298R

    Please refer to Page 18 7.8 Typical Characteristics; for additional, developers and designers may have to use evaluation kit/board(EVM) and/or customer board to do further investigation.

    And, the tests conditions that can be disclosed are already listed in datasheet -

    "

    Min and max specifications apply for all commercial grade (TA = 0°C to 70°C) devices, and from TA = –40°C to +85°C for industrial-grade devices. Typical specifications at TA = 25°C. All specifications at DVDD = 1.8 V, AVDD – AVSS = 3 V (1) , VREF = 2.4 V, external fCLK = 2.048 MHz, data rate = 500 SPS, HR mode(2) , and gain = 6 (unless otherwise noted).

    "

     and

    "

    at TA = 25°C, AVDD = 3 V, AVSS = 0 V, DVDD = 1.8 V, internal VREFP = 2.4 V, VREFN = AVSS, external clock = 2.048 MHz, data rate = 500 SPS, high-resolution mode, and gain = 6 (unless otherwise noted)

    " 

    2) Similar to 1), however, TI cannot disclose the exact test setup and procedures that were used to characterize the chip as they were done in a particular Lab environment and test setup.

    And, the tests conditions that can be disclosed are already listed in datasheet -

    "

    Min and max specifications apply for all commercial grade (TA = 0°C to 70°C) devices, and from TA = –40°C to +85°C for industrial-grade devices. Typical specifications at TA = 25°C. All specifications at DVDD = 1.8 V, AVDD – AVSS = 3 V (1) , VREF = 2.4 V, external fCLK = 2.048 MHz, data rate = 500 SPS, HR mode(2) , and gain = 6 (unless otherwise noted).

    "

     and

    "

    at TA = 25°C, AVDD = 3 V, AVSS = 0 V, DVDD = 1.8 V, internal VREFP = 2.4 V, VREFN = AVSS, external clock = 2.048 MHz, data rate = 500 SPS, high-resolution mode, and gain = 6 (unless otherwise noted)

    "

    However, Customer could use an evaluation board and/or develop their own board to do some characterization and to see whether the results meet the needs.

    3) People who needs/wants to do this will then need to create or have a thermal cycle/test environment.

    4) I will need to discuss with the internal team to see whether we can disclose how to retrieve input impedance and get back to you.

    5) Would you please explain a bit more what you mean and what you want to try or achieve?

    ADS1298(R) can be used to design product(s) that meet iec60601. However, it's developer's and designer's responsibilities to design final product(s) to meet the iec60601.

    Thanks