Power-Supply

ESD Cell

2.5

NŸ

2.5

NŸ

IN

±

IN+

R1

RS

RF

TVS

RL

VIN

±VS

ID

+

±

TVS

+VS

+

18

TLV170, TLV2170, TLV4170

SBOS782A – NOVEMBER 2016 – REVISED MAY 2018

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Product Folder Links: TLV170 TLV2170 TLV4170

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Copyright © 2016–2018, Texas Instruments Incorporated

Feature Description (continued)

Figure 27. Equivalent Internal ESD Circuitry Relative to a Typical Circuit Application

An ESD event produces a short-duration, high-voltage pulse that is transformed into a short-duration, high-

current pulse when discharging through a semiconductor device. The ESD protection circuits are designed to

provide a current path around the op amp core to prevent damage. The energy absorbed by the protection

circuitry is then dissipated as heat.

When an ESD voltage develops across two or more amplifier device pins, current flows through one or more

steering diodes. Depending on the path that the current takes, the absorption device can activate. The absorption

device has a trigger, or threshold voltage, that is above the normal operating voltage of the TLVx170 but below

the device breakdown voltage level. When this threshold is exceeded, the absorption device quickly activates

and clamps the voltage across the supply rails to a safe level.

When the op amp connects into a circuit, as shown in Figure 27, the ESD protection components are intended to

remain inactive and do not become involved in the application circuit operation. However, circumstances can

arise where an applied voltage exceeds the operating voltage range of a given pin. If this condition occurs, there

is a risk that some internal ESD protection circuits can turn on and conduct current. Any such current flow occurs

through steering-diode paths and rarely involves the absorption device.

Figure 27 shows a specific example where the input voltage (VIN) exceeds the positive supply voltage (V+) by

500 mV or more. Much of what happens in the circuit depends on the supply characteristics. If V+ can sink the

current, then one of the upper input steering diodes conducts and directs current to V+. Excessively high current

levels can flow with increasingly higher VIN. As a result, the data sheet specifications recommend that

applications limit the input current to 10 mA.

If the supply is not capable of sinking the current, VIN can begin sourcing current to the op amp and then take

over as the source of positive supply voltage. The danger in this case is that the voltage can rise to levels that

exceed the op amp absolute maximum ratings.