Data Sheet

MAX74821

analog.com

Rev. 0

12 of 15

APPLICATIONS INFORMATION

Output Phase Reversal

Phase reversal is defined as a change in polarity at the output of the amplifier when a voltage that exceeds the

maximum input common-mode voltage drives the input.

Phase reversal can cause permanent damage to the amplifier; it can also cause system lockups in feedback loops.

The MAX74821 does not exhibit phase reversal even for inputs exceeding the supply voltage by more than 2 V.

Maximum Power Dissipation

Power dissipated in an IC causes the die temperature to increase, which can affect the behavior of the IC and the

application circuit performance.

The absolute maximum junction temperature of the MAX74821 is 150°C. Exceeding this temperature can damage or

destroy the device.

The maximum power dissipation of the amplifier is calculated according to:

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where:

TJ is the junction temperature.

TA is the ambient temperature.

θJA is the junction-to-ambient thermal resistance.

Input Overvoltage Protection

The MAX74821 has internal protective circuitry. However, if the voltage applied at either input exceeds the supplies

by more than 0.3V, external resistors should be placed in series with the inputs. The resistor values can be

determined by:

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≤ 10mA

The remarkable low input offset current of the MAX74821 (<1pA) allows the use of larger value resistors. With a 10kΩ

resistor at the input, the output voltage has less than 10nV of error voltage.

A 10kΩ resistor has less than 13nV/√Hz of thermal noise at room temperature.