SHORT-CIRCUIT

CURRENT LIMIT

SHORT-CIRCUIT

REMOVED

100 mV

LM21212-2

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SNVS715A – MARCH 2011 – REVISED MARCH 2013

Figure 23. Current Limit Conditions

THERMAL PROTECTION

Internal thermal shutdown circuitry is provided to protect the integrated circuit in the event that the maximum

junction temperature is exceeded. When activated, typically at 165°C, the LM21212-2 tri-states the power FETs

and resets soft start. After the junction cools to approximately 155°C, the device starts up using the normal start

up routine. This feature is provided to prevent catastrophic failures from accidental device overheating. Note that

thermal limit will not stop the die from operating above the specified operating maximum temperature,125°C. The

die should be kept under 125°C to ensure correct operation.

POWERGOOD FLAG

The PGOOD pin provides the user with a way to monitor the status of the LM21212-2. In order to use the

PGOOD pin, the application must provide a pull-up resistor to a desired DC voltage (i.e. Vin). PGOOD will

respond to a fault condition by pulling the PGOOD pin low with the open-drain output. PGOOD will pull low on

Figure 24 shows the conditions that will cause PGOOD to fall.

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