LP3988

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SNVS161E – OCTOBER 2001 – REVISED OCTOBER 2015

Feature Description (continued)

8.3.5 Current Limit

maximum amount of current the device can source is typically 600 mA, and is largely independent of input and

output voltage. For reliable operation, do not operate the device in current limit for extended periods of time.

Depending on power dissipation, thermal resistance, and ambient temperature, operating at the current limit may

activate the thermal shutdown circuitry.

160°C, This shutdown causes the device dissipation to go to zero, which allows the device to cool. When the

device junction temperature cools to approximately 140°C, the output circuitry is automatically enabled.

Depending on power dissipation, thermal resistance, and ambient temperature, the thermal protection circuit may

cycle ON and OFF. This cycling limits the dissipation of the regulator, protecting it from damage as a result of

overheating. The thermal shutdown circuitry of the LP3988 has been designed to protect against temporary

8.3.7 Fast Turnon Time

output turnon time.

8.4 Device Functional Modes

8.4.1 Normal Operation

The device regulates to the nominal output voltage under the following conditions:

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The output current is no more than the maximum rated current of 150 mA.

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8.4.2 Dropout Operation

conditions are met for normal operation, the device operates in dropout mode. In this mode of operation, the

output voltage is the same as the input voltage minus the dropout voltage. The transient performance of the

device is significantly degraded because the pass device (PMOS transistor), no longer controls the current

through the LDO. Line or load transients while operating in dropout can result in large output voltage deviations.

8.4.3 Disabled

The device is disabled under the following conditions:

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