Application information

STCS1A

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8

Application information

8.1

Reverse polarity protection

STCS1A must be protected from reverse connection of the supply voltage. Since the current

protect the chip. Care must be taken for the whole application circuit, especially for the

voltage will be applied to the LED string that must have a total breakdown voltage higher

than the negative applied voltage in order to avoid any damage.

8.2

Thermal considerations

The STCS1A is able to control a LED current up to 1.5 A and able to sustain a voltage on

the drain pin up to 40 V. Those operating conditions are however limited by thermal

constraints, the thermal resistances shown in the Thermal data section are the typical ones,

circuit board under the pad. DFN8 and PowerSO-8 have an exposed die attach pad which

enhances the thermal conductivity enabling high power application.

The power dissipation in the device can be calculated as follow:

basing on this and on the thermal resistance and ambient temperature, the junction

temperature can be calculated as:

A typical application could be:

– Input voltage: 12 V;

Figure 15.

Reverse polarity condition

PWM

EN

GND

SLOPE

V

CC

DRAIN

DISC

FB

V

IN

+

or similar

BAT46

PWM

EN

GND

SLOPE

V

CC

DRAIN

DISC

FB

V

IN

+

or similar

PWM

EN

GND

SLOPE

V

CC

DRAIN

DISC

FB

V

IN

+

or similar

BAT46

PWM

EN

GND

SLOPE

V

CC

DRAIN

DISC

FB

V

IN

+

or similar