# ABSOLUTE MAXIMUM RATINGS of ADG884 INx pin

I'm DFAE in Japan. My customer asked me what are meanings of ABSOLUTE MAXIMUM RATINGS in the datasheet of ADG884.

ABSOLUTE MAXIMUM RATINGS of ADG884 are described as follows.

Analog Inputs,(1) Digital Inputs −0.3 V to VDD + 0.3 V or 30 mA (whichever occurs first)

(1)Overvoltages at IN, S, or D pins are clamped by internal diodes. Current should be limited to the maximum ratings given.

When my customer measured I-V between INx and VDD, he could NOT find diode characteristics in ±1V.

Does INx pin has the protection diode between INx and VDD?

Or INx pin have clamp diode between INx and GND to clamp INx voltage?

Parents
• Hi,

The INx pin has an internal protection diode tied to VDD. This allows the digital input to swing from -0.3 V to VDD+0.3 V range as stated in the absolute maximum rating section of the datasheet.

Best regards,
Christian

• I connected 3.3V to VDD and 0V to GND.

And I added sine signal with DC bias.

I could find diode characteristics between INx and GND in Figure1

But, I cound NOT find it between INx and VDD in Figure2.

Does ADG884 has the protection diode between INx and VDD?

Is VDD+0.3 V really the absolute maximum rating of INx ?

Figure1 ch1 INx ch2 VDD

Figure2 ch1 INx ch2

• What are the amplitudes and that you've used in the sine wave signal and the DC bias?

• you can find amplitude and offset voltage in the graphs.

In Figure2, VDD=3.3V and INx is 3.9+/- 1V

In Figure1, INx is 0 +/- 1V

• Hi,

Why do they use 3.9 V at the INx of the ADG884? Where does the switch digital input is interfaced?

Note that the switch has internal clamp diodes that allow the INx to operate up to VDD+0.3 V. The clamping of the voltage at the INx will not be visible in the scope even you tap it to the INx input. You can check the amount of current that you are sourcing in the INx pin and if the device increases its temperature.

Have they checked the response of the analog input (source) and output(drain) when the INx pin is at 3.9 V +/-1 V? Do they get the same response?

Note this section in the datasheet when operating above the absolute maximum rating:

Best regards,
Christian

• Hi,

Why do they use 3.9 V at the INx of the ADG884? Where does the switch digital input is interfaced?

Note that the switch has internal clamp diodes that allow the INx to operate up to VDD+0.3 V. The clamping of the voltage at the INx will not be visible in the scope even you tap it to the INx input. You can check the amount of current that you are sourcing in the INx pin and if the device increases its temperature.

Have they checked the response of the analog input (source) and output(drain) when the INx pin is at 3.9 V +/-1 V? Do they get the same response?

Note this section in the datasheet when operating above the absolute maximum rating:

Best regards,
Christian

Children
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