TS19376

1A Step-down High Brightness LED Driver

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Version: A12

Application Information (Continue)

Operation at low supply voltage

The internal regulator disables the drive to the switch until the supply has risen above the startup threshold

(VUVLO). Above this threshold, the device will start to for this reason, the temperature coefficients of the operating.

However, with the supply voltage below the specified minimum value, the switch duty cycle will be high and the

device power dissipation will be at a maximum. Care should be taken to avoid operating the device under such

conditions in the application, in order to minimize the risk of exceeding the maximum allowed die temperature. (See

next section on thermal considerations). The drive to the switch is turned off when the supply voltage falls below

the under-voltage threshold (VUVLO-1V).

This prevents the switch working with excessive 'on' resistance under conditions where the duty cycle is high.

Thermal shutdown protection

To ensure the reliability, the TS19376 is built with a thermal shutdown (TSD) protection function. The TSD protests

the IC from over temperature (150°C). When the chip temperature decreases (115°C), the IC recovers aga in.