The CAT4109 is a 3-channel constant-current LED driver, requiring no inductor. LED channel currents up to 175 mA are programmed independently via separate external resistors. Low output voltage operation of 0.4 V at 175 mA allows for more power efficient designs across wider supply voltage range. The three LED pins are compatible with high voltage up to 25 V supporting applications with long strings of LEDs.
Three independent control inputs PWM1, PWM2, PWM3, control respectivelly LED1, LED2, LED3 channels. The device also includes an output enable (OE) control pin to disable all three channels independently of the PWMx input states.
Thermal shutdown protection is incorporated in the device to disable the LED outputs whenever the die temperature exceeds 150°C.

• 3 independent current sinks up to 175 mA rated 25 V
• LED current set by external low power control resistors
• Individual PWM control per channel
• Low dropout current source (0.4 V at 175 mA)
• Output Enable input for dimming
• 'Zero' current shutdown mode
• 3 V to 5.5 V logic supply
• Thermal shutdown protection