OPA828 datasheet(17/47 Pages) TI

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7.3 Feature Description

7.3.1 Phase-Reversal Protection

Many operational amplifiers exhibit a phase reversal when the input drives beyond the specified input common-

mode range. This condition is most often encountered in noninverting circuits when the input drives beyond

the specified common-mode voltage range, which can cause the output to reverse into the opposite rail. The

OPAx828 have an internal phase-reversal protection circuitry. The input architecture of the OPAx828 prevents

phase reversal with input common-mode voltages that exceed the specified maximum and minimum values.

The OPAx828 output limits to the appropriate rail. Figure 7-1 shows this performance. When input voltages can

exceed the minimum or maximum specified limits, make sure to limit the maximum input current through internal

ESD protection diodes.

Time (200 Ps/div)

Input

Output

Figure 7-1. No Phase Reversal

7.3.2 Electrical Overstress

The OPAx828 are internally protected against electrostatic discharge (ESD) events that can occur during

manufacturing, handling, or printed-circuit-board (PCB) assembly. The internal ESD protection diodes are not

intended to protect the OPAx828 during normal operation when the devices are operating under power. The ESD

protection circuitry involves several current-steering diodes connected from the input and output pins and routed

back to the internal power-supply lines, where the diodes meet at the power-supply ESD cell, an absorption

device, internal to the operational amplifiers. This protection circuitry is intended to remain inactive during normal

circuit operation. In cases where the inputs or output can be driven above the positive power supply or below

the negative power supply, make sure to limit the current through the internal diodes to 10 mA or less. In harsh

electrical environments, external protection circuitry can be required depending on the application requirements

and environmental conditions.

+IN

-IN

V+

V-

OUT

Figure 7-2. Equivalent Internal ESD Circuitry

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OPA828, OPA2828

SBOS671D – SEPTEMBER 2018 – REVISED DECEMBER 2022

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OPA828 Datasheet(PDF) 17 Page - Texas Instruments