ADS124S06: ADS124S06 Protection diode

Masa Katayama

Intellectual 970 points

Part Number: ADS124S06

Dear Sir,

May I ask if external protection diodes are required for both AINX and REFP Analog input?

Absolute Maximum Ratings in datasheet limits specifically Analog input voltage for above pins.

But figure 49 on page 32 shows that AIN pins already has the diode inside.

and how about REFP/N pins. (I could not find figure the block diagram inside.)

I limit input current by current limit resistances anyway.

Best regards,

Masa

over 5 years ago

0 Bob Benjamin over 5 years ago

TI__Guru** 113765 points

Hi Masa-san,

The ADS124S06 has ESD Ratings as shown in section 7.2 of the datasheet. Although not specifically stated the ESD protection is implied on all analog and digital pins by the Absolute Maximum Ratings where the ESD diodes begin to conduct around 300mV from the supply rails. The ADS124S06 ESD protection is not necessarily good in a system environment, but rather for handling during manufacturing. ESD events within a system can be much higher than the device ratings depending on the operating environment.

Series resistance must be high enough to limit current to 10mA through the device pins in over-voltage conditions. Depending on operating environment some other additional circuitry may be required as the resistor protection may not be enough on its own if it is the sole protection method. This may require protection from other sources that can include TVS diodes and/or some other low leakage diodes such as BAV199. Leakage can cause measurement error, so leakage specifications must be taken into account.

Best regards,
Bob B

0 Masa Katayama over 5 years ago in reply to Bob Benjamin

Intellectual 970 points

Bob,
Thank you very much for your answer!
Masa

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ADS124S06: ADS124S06 Protection diode