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How do I protect my ADC?
To protect the input of the ADC, the TVS diode breakdown voltage should never be lower than the absolute maximum ratings for the ADC. For example, if the absolute maximum rating of the ADC is plus/minus 15 volts, the breakdown voltage should be a lower voltage, such as plus/minus 12 volts.
How do you protect inputs on a microcontroller?
The simplest protection mechanism is a current limiting resistor, as shown in Figure 6. The input resistor is sized so that the voltage drop across it does not affect the voltage at the microcontroller input.
How can we avoid over voltage?
5 Ways You Can Prevent Over Voltage
- Take note of your appliances’ voltage requirements.
- Use transformers properly.
- Be careful when dealing with insulators.
- Stop using appliances when there is a storm.
- Consult with experts regularly.
How to protect ADC inputs from overvoltage?
A common issue that arises when designing an ADC circuit is how to protect the ADC inputs from overvoltage. The protection of ADC inputs has many scenarios and potential solutions. ADCs from all vendors have similar needs in this respect.
How big is an input resistor in a microcontroller?
The input resistor is sized so that the voltage drop across it does not affect the voltage at the microcontroller input. As this is a simple voltage divider, and the input resistance in the controller is about 20 MΩ, this resistor can be fairly big. For most digital inputs, a good value is between 100 Ω and 10 kΩ.
How does the series resistor protect the ADC?
The series resistor after the Schottky diodes also helps limit the current into the ADC if the internal diodes turn on slightly. For extra protection, if the reference has little to no sink current capability, a Zener diode or clamp circuit could be used on the reference node to guarantee the reference voltage cannot be pulled too high.
How does an input clipping diode protect the input?
Figure 13: Reading high voltage inputs. The input clipping diode to ground is to protect from less than zero volt spikes. The input clipping diode to the positive bus is removed in favor of the zener diode after the current limiting resistor. This provides a known voltage for the input pin and reduces the amount of current shunted to the power bus.