6.3.2 Thermal Protection

The OPAx596 has a thermal protection feature that prevents damage from self heating. When the junction

temperature (TJ) reaches approximately 180ºC, the op amp output stage disables. This thermal protection works

by monitoring the temperature of the output stage and turning off the op amp output drive. Thermal protection

forces the output to a high-impedance state. The OPAx596 is designed with approximately 30°C of thermal

hysteresis and returns to normal operation when the output stage temperature becomes less than approximately

150°C.

This thermal protection is not designed to prevent this device from exceeding absolute maximum ratings, but

rather from excessive thermal overload.

6.3.3 Slew Boost

Slew rate is the maximum rate of change of output voltage change with respect to time and is typically specified

in units of volts per microsecond, V/µs. The OPAx596 can enter a slew condition when a large, rapid moving

signal is applied at the input. While slewing, the op amp enters an open loop condition and significant slew

induced distortion can be seen on the output signal.

Equation 1 shows that the slew rate of an op amp is typically determined by the saturation current of the input

stage, ISAT, and the compensation capacitor, CC.

SR=ISATCC

(1)

The slew rate scales with the quiescent current, IQ, of the op amp. There are several ways that designers have

overcome slew rate limitation. For example, decompensation improves slew rate at the expense of stability by

lowering CC. More commonly, modern op amps are equipped with slew boost technology that increases ISAT to

overcome the inherent slew rate limitations. Slew boost circuits can vary in implementation, but designers can

typically expect about a 4 × improvement over comparable unboosted op amps.

The OPAx596 uses a proprietary design to achieve an unprecedented slew rate to IQ ratio. The novel slew boost

technology in OPAx596 provides a nearly 100 × slew rate improvement over comparable unboosted op amps.

6.3.4 Overload Recovery

Overload recovery is defined as the time required for the op amp output to recover from a saturated state to

a linear state. The output devices of the op amp enter a saturation region when the output voltage exceeds

the rated operating voltage, either due to the high input voltage or the high gain. After the device enters the

saturation region, the charge carriers in the output devices require time to return back to the linear state. After

the charge carriers return back to the linear state, the device begins to slew at the specified slew rate. Thus, the

propagation delay in case of an overload condition is the sum of the overload recovery time and the slew time.

6.4 Device Functional Modes

The OPAx596 has a single functional mode and is operational when the power-supply voltage is between 8V

(±4V) and 85V (±42.5V).

www.ti.com

OPA596

SBOSA42 – JUNE 2024

Copyright © 2024 Texas Instruments Incorporated

Submit Document Feedback

9

Product Folder Links: OPA596