Datasheet

5kW
Device
10mAmax
V+
V
IN
V
OUT
I
OVERLOAD
OPA1652
OPA1654
www.ti.com SBOS477 –DECEMBER 2011
POWER DISSIPATION
The OPA1652 and OPA1654 series op amps are
capable of driving 2-kΩ loads with a power-supply
voltage up to ±18V and full operating temperature
range. Internal power dissipation increases when
operating at high supply voltages. Copper leadframe
construction used in the OPA165x series op amps
improves heat dissipation compared to conventional
materials. Circuit board layout can also help minimize
Figure 40. Input Current Protection
junction temperature rise. Wide copper traces help
dissipate the heat by acting as an additional heat
An ESD event produces a short duration,
sink. Temperature rise can be further minimized by
high-voltage pulse that is transformed into a short
soldering the devices to the circuit board rather than
duration, high-current pulse as it discharges through
using a socket.
a semiconductor device. The ESD protection circuits
are designed to provide a current path around the
ELECTRICAL OVERSTRESS
operational amplifier core to prevent it from being
damaged. The energy absorbed by the protection
Designers often ask questions about the capability of
circuitry is then dissipated as heat.
an operational amplifier to withstand electrical
overstress. These questions tend to focus on the
When the operational amplifier connects into a circuit,
device inputs, but may involve the supply voltage pins
the ESD protection components are intended to
or even the output pin. Each of these different pin
remain inactive and not become involved in the
functions have electrical stress limits determined by
application circuit operation. However, circumstances
the voltage breakdown characteristics of the
may arise where an applied voltage exceeds the
particular semiconductor fabrication process and
operating voltage range of a given pin. Should this
specific circuits connected to the pin. Additionally,
condition occur, there is a risk that some of the
internal electrostatic discharge (ESD) protection is
internal ESD protection circuits may be biased on,
built into these circuits to protect them from
and conduct current. Any such current flow occurs
accidental ESD events both before and during
through ESD cells and rarely involves the absorption
product assembly.
device.
These ESD protection diodes also provide in-circuit,
If there is an uncertainty about the ability of the
input overdrive protection, as long as the current is
supply to absorb this current, external zener diodes
limited to 10 mA as stated in the Absolute Maximum
may be added to the supply pins. The zener voltage
Ratings. Figure 40 shows how a series input resistor
must be selected such that the diode does not turn
may be added to the driven input to limit the input
on during normal operation.
current. The added resistor contributes thermal noise
However, its zener voltage should be low enough so
at the amplifier input and its value should be kept to a
that the zener diode conducts if the supply pin begins
minimum in noise-sensitive applications.
to rise above the safe operating supply voltage level.
Copyright © 2011, Texas Instruments Incorporated 15
Product Folder Link(s): OPA1652 OPA1654