U S I N G L E D s in the conventional way - with resistors as the current limiting
element - results in varying current with small changes in the supply voltage due to
the small differential resistance of the LED. The TLE 4242 drives LEDs with constant
current resulting in constant brightness and extended life times. The TLE 4242 is fully
capable to withstand harsh automotive requirements due to its internal protection
circuits against overload, short circuit, reverse polarity, and overtemperature.
A status output allows LED-fault handling.
Due to the high input impedance of the PWM input the LED driver can be operated
as a protected high side switch.
With the PWM input the LED brightness can be regulated via duty cycle.
Also PWM = L sets the TLE 4242 in sleep mode resulting in a very low cur rent
consumption of <<1 μA typ. Due to the high impedance of the PWM input the PWM
pin can thus also be used as an enable input.
Applications for LED Driver
■ Brake Light
■ Fog Light
■ Turn signal (flasher)
■ Tail lights
■ Day lights
■ Running lights/reverse light/
license plate light
■ Airbag Sensor supply
■ Traffic Lights
■ Street marker lights
■ Emergency lightning