Category: Datasheet/Specs
Product Number: AD5592r
Good day,
I would like to know if the AD5592 can tolerate any current into the pin (from an input voltage higher than VDD), and what the maximum is.
Relevant information I can find in the datasheet is from the abs maximum ratings:
- "Transient currents of up to 100mA do not cause SCR latch-up." but I am not sure where that transient current is allowed to flow. I am going to start by assuming that I cannot put 100mA into an I/O pin.
- "Analog Input Voltage to GND −0.3 V to VDD + 0.3 V" from which I assume that there are clamping diodes to VDD and GND.
From the Specifications section we have:
- Input Range: 0V (minimum) to VREF(maximum)
We are powering the device with 3V3 and using the internal 2V5 reference, with a typical voltage divider to get V_measure into the range 0 to Vref. My assumptions from the datasheet items mentioned above are:
- input = 0V to Vref: good analog measurement
- input = Vref to 3V3: analog measurement saturates to max value, but no other bad effects
- input > Vdd: pin clamps to Vdd and current into pin limited by external resistor
Questions are:
- Which of the above assumptions are correct/not correct?
- What is the maximum clamping current before the device is damaged?
- If the device is clamping, are there any effects on any other channels? (I have worked with a microprocessor where the injection current (within spec) did not damage the device, but conversion values for other channels were significantly (-35%) affected.)
- Does any of the above depend on whether the internal buffer is used or not?
Many thanks
