GENERAL DESCRIPTION

The AD8240 LED driver/monitor, in combination with an external transistor, supplies a constant 12 V to drive LED lamps. This allows cost-effective LED lamp monitoring and short-circuit protection. The output is regulated at 12 V when the supply voltage is between 12.5 V and 27 V.

A CMOS compatible, level-dependent, digital input can be used for PWM control of the LED brightness. VOis turned on when the PWM input is high and turned off when the input is low. The AD8240 is designed to work with a PWM frequency up to 500 Hz, and a typical PWM range from 5% to 95%.

FEATURES

PWM input for LED brightness control

Open LED detection

Latch-off overcurrent protection

Constant voltage regulated output

Supply range: 9 V to 27 V

Regulated voltage range: 12.5 V to 27 V

Operating current: 300 µA

Shutdown current: 10 µA

Temperature range −40°C to +125°C

8-lead MSOP package