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OPA521

SBOS872 – MAY 2018

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ILIM Pin Current Limiting (continued)

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7.7 IFLAG and TFLAG Pins

The IFLAG and TFLAG pins are active-high, open-drain outputs that indicate if the OPA521 is in current or

thermal limit. Connect these pins to 3.3 V through pullup resistors (for example 10 kΩ).

connected between ILIM (pin 12) and ground. IFLAG is set if the amplifier goes to a current limit state if a fault

condition occurs. This causes the PA to source or sink more current than the programmed limit value. IFLAG

exhibits transient pulses under typical operation. An IFLAG true state for greater than 100 ms is a definite

indication of a fault current condition.

The device contains internal thermal shutdown protection circuitry that automatically disables the output stage if

the junction temperature exceeds 165°C. The device thermal shutdown protection circuitry lets the amplifier

typical normal operation only when the junction temperature falls below 150°C. The TFLAG is active when the

device is in thermal shut down mode.

7.8 Device Functional Modes

The OPA521 operates from a single power rail from 7 V to 24 V. The gain is set at –7 V/V and can increase with

an external resistor that is connected to the GAIN_SET and –IN pins.