Part Number: MSP432E401Y
I am using the MSP432E401Y in an embedder data acquisition application, and need to understand the analog input circuits.
In some, limited instances, an input signal might exceed Vdda for a short time. All signals are current limited by source impedance, but what are the limits the device can withstand?
The analog inputs I have exercised and instrumented have clamping diodes to protect the device from excess voltages. Measuring the input at the uC pin shows a maximum of about 400mV above Vdda.
(Vdda at 3.3V, input up to ~4V through 10k series resistor, externally measured input voltage at the pin ~3.7V. Estimated input current about 40 microamps)
Questions:
1. What is the maximum safe limit on excessive input current through those diodes?
2, Input resistance (~2.5k) specifies series resistance. Is there a spec for input impedance referred to Analog return (shunt impedance)?
Thank you!
