The CAT3626 is a high efficiency 1x/1.5x fractional charge pump with programmable dimming current in six LED channels. To ensure uniform brightness in LCD backlight applications, each LED channel delivers an accurate regulated current.
Low noise and input ripple is achieved by operating at a constant switching frequency of 1MHz which allows the use of small external ceramic capacitors. The 1x/1.5x fractional charge pump supports a wide range of input voltages from 3V to 5.5V with efficiency up to 91%, and is ideal for Li-Ion battery powered devices.
The LED channels are configured into three independent pairs, each containing 2 matched channels. Each pair can be separately programmed from zero to 32 mA, in 0.5 mA resolution steps, using the I2C serial interface. Any individual channel can be disabled while others remain active. When the enable input (EN) is low, the device is in shutdown mode drawing zero current.

• Drives 6 LED channels
• Independent current on 3 pairs of LEDs
• I2C serial interface programming
• Adjustable current to 32 mA in 0.5 mA steps
• Power efficiency up to 91%
• Fractional pump 1x/1.5x
• Low noise input ripple
• Fixed High Frequency Operation 1MHz
• “Zero” Current Shutdown Mode
• Soft start and current limiting
• Short circuit protection
• Thermal shutdown protection