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ADS1298R: ADS1298R VIH and VIL

Part Number: ADS1298R
Other Parts Discussed in Thread: ADS1298

Hello,

I'm working with the ADS1298R powered by 3V on AVDD and 2.4V on DVDD and connected to a 2.4V powered MCU.

Referring to the datasheet the High-level Input Voltage is :     0.8*VDD < Vih < DVDD + 0.1. How I should understand this ? Should I ensure to have a minimum of 2.5V (DVDD+0.01) on my Input signal to be sure that the ADS1298 will understand a "1" ? Or the "min" and "max" are only a range where we should be ?

In the first case my input be be higher than the DVDD power supply of the ADS1298, is that ok ?

I also have the same question regarding VIL min and max

 

Thank you in advance for your answer and time !

Best regards

  • Hi Khaled,

    Welcome to the E2E forum and using the ADS1298 in your system.

    For the ADS1298 to recognize a high-level input (V_IH), the digital input voltage must be a minimum of DVDDx0.8 or 1.92V for your case of DVDD=2.4V. Anything higher than DVDDx0.8 is fine, but it should not exceed DVDD + 0.1V (V_IH max) or 2.5V in your system.

    Likewise, a low-level input (V_IL) must be no greater than 0.2xDVDD. Lower than 0.2xDVDD is also fine, but do not go below -0.1V. 

    Between 0.2xDVDD and 0.8xDVDD, the logic level which ADS1298 reads will be undetermined. 

    Thanks.

    -TC