CAT3649AGEVB: High Efficiency Quad-Mode Fractional Charge Pump Evaluation Board

The CAT3649 is a high-efficiency quad-mode fractional charge pump that can drive up to six LEDs. Using the 1.33x fractional charge pump mode improves the device efficiency by 10% over conventional 1.5x charge pumps without the need to add external capacitors. Low noise input ripple is achieved by operating at a constant switching frequency, allowing the use of small external ceramic capacitors. The multi-fractional charge pump supports a wide range of input voltages from 2.4 V to 5.5 V. The LED current can be adjusted in different ways. Once the device is enabled, the full-scale LED current is set to 25 mA. Analog dimming in 32 linear steps is achieved through a single-wire pulse dimming input (ADIM). The LED current can be further adjusted by applying a pulse width modulation (PWM) signal on the PWM input. The PWM dimming control is compatible with content adaptive brightness control (CABC) and the PWM signal frequency range is up to 200 kHz.


The CAT3649 is a high efficiency Quad-Mode fractional charge pump that can drive up to six LEDs. The inclusion of a 1.33x fractional charge pump mode increases the device efficiency by up to 10% over traditional 1.5x charge pumps with no added external capacitors. Low noise input ripple is achieved by operating at a constant switching frequency which allows the use of small ceramic external capacitors. The multi-fractional charge pump supports a wide range of input voltages from 2.4 V to 5.5 V.The LED current can be adjusted in different ways. The full-scale LED current is set to 25 mA once the device is enabled. Analog dimming in 32 linear steps is achieved via a 1-wire pulse-dimming input (ADIM). Further adjustment of the LED current can be done by applying a pulse width modulation (PWM) signal on the PWM input. The PWM dimming control is compatible with content adaptive brightness control (CABC) for a wide range of PWM signal frequency up to 20 0kHz.