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How to protect ADC inputs?
The most common is to use Schottky diodes (BAT54 series) to clamp the output of the amplifier to the range of the ADC. See Figure 2 and Figure 3 for an illustration. It may also be possible to use diodes to clamp the input to the amplifier if it suits the application needs.
How to damage an op amp?
Excessive input current over long periods of time or even short periods of time, if the current is high enough, can damage the op amp. This damage can result in a shift in the electrical specification parameters beyond the data sheet’s guaranteed limits; it can even cause a permanent failure of the op amp.
Can diodes provide gain?
Potential advantages in the use of diode amplifiers in such applications as modulators and frequency converters are indicated. This circuit configuration has an output impedance which is larger than its input impedance, and provides voltage gain aimilar to a common base transistor amplifier.
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 is series Your used to protect ADC inputs?
The series R in the RC filter between the amplifier and the ADC input can also be used to limit the current seen at the ADC input during an overvoltage condition. However, this will be a trade-off between current limiting and ADC performance. Larger series R will give better input protection but result in greater distortion in the ADC performance.
How is the ada4177 op amp overvoltage protected?
The ADA4177 is a high precision op amp that includes integrated overvoltage protection. The integrated ESD diodes act as overvoltage clamps to protect the part. Depletion mode FETs are in series at each input before the ESD diodes. They provide the dynamic resistance, which increases when the input voltage (V CM) exceeds the supply voltages.
When does overdrive of ADC inputs take place?
Overdrive of ADC inputs generally occurs when the rails of the driving amplifier are significantly greater than the max input range of the ADC—for example, if the amplifier runs from ±15 V and the ADC input is 0 V to 5 V.