Datasheet

OPA1611
OPA1612
SBOS450B –JULY 2009–REVISED JULY 2011 www.ti.com
POWER DISSIPATION It is helpful to have a good understanding of this
basic ESD circuitry and its relevance to an electrical
OPA1611 and OPA1612 series op amps are capable
overstress event. Figure 34 illustrates the ESD
of driving 2kΩ loads with a power-supply voltage up
circuits contained in the OPA161x series (indicated
to ±18V. Internal power dissipation increases when
by the dashed line area). The ESD protection circuitry
operating at high supply voltages. Copper leadframe
involves several current-steering diodes connected
construction used in the OPA1611 and OPA1612
from the input and output pins and routed back to the
series op amps improves heat dissipation compared
internal power-supply lines, where they meet at an
to conventional materials. Circuit board layout can
absorption device internal to the operational amplifier.
also help minimize junction temperature rise. Wide
This protection circuitry is intended to remain inactive
copper traces help dissipate the heat by acting as an
during normal circuit operation.
additional heat sink. Temperature rise can be further
minimized by soldering the devices to the circuit An ESD event produces a short duration,
board rather than using a socket. high-voltage pulse that is transformed into a short
duration, high-current pulse as it discharges through
a semiconductor device. The ESD protection circuits
ELECTRICAL OVERSTRESS
are designed to provide a current path around the
Designers often ask questions about the capability of
operational amplifier core to prevent it from being
an operational amplifier to withstand electrical
damaged. The energy absorbed by the protection
overstress. These questions tend to focus on the
circuitry is then dissipated as heat.
device inputs, but may involve the supply voltage pins
When an ESD voltage develops across two or more
or even the output pin. Each of these different pin
of the amplifier device pins, current flows through one
functions have electrical stress limits determined by
or more of the steering diodes. Depending on the
the voltage breakdown characteristics of the
path that the current takes, the absorption device
particular semiconductor fabrication process and
may activate. The absorption device internal to the
specific circuits connected to the pin. Additionally,
OPA1611 triggers when a fast ESD voltage pulse is
internal electrostatic discharge (ESD) protection is
impressed across the supply pins. Once triggered, it
built into these circuits to protect them from
quickly activates and clamps the ESD pulse to a safe
accidental ESD events both before and during
voltage level.
product assembly.
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