描述 Description

The CAT3649 is a high efficiency 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 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. 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 200 kHz.The CAT3649 can be shut down by holding the ADIM or PWM input in a logic low condition for greater than 30 ms.

特性 Features

? High Efficiency 1.33x Charge Pump
? Highest efficiency charge pump.
? Drives up to 6 LEDs at 25 mA Each
? Compatible with larger size LCD used in smartphones.
? PWM Dimming 100 Hz to 200 kHz for CABC
? PWM dimming control compatible with content adaptive brightness control (CABC).
? Quad-mode Charge Pump: 1x, 1.33x, 1.5x, 2x
? 1-wire EZDimTM 32 Linear Steps (ADIM)
? Power Efficiency up to 92%
? Low Noise Input Ripple in All Modes
? Zero Current Shutdown Mode
? Soft Start and Current Limiting
? Short Circuit Protection
? Thermal Shutdown Protection

應(yīng)用 Application

? LCD Display Backlight
? Mobile Phones
? Digital Still Cameras

簡介

CAT3649屬于集成電路（IC）的LED驅(qū)動器。由制造生產(chǎn)的CAT3649LED 驅(qū)動器器件屬于 LED 驅(qū)動器電源管理集成電路 (PMIC) 系列，可通過標稱固定電壓的電源為負載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調(diào)節(jié)的類似產(chǎn)品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通?？蓪ζ骷ぷ鼽c進行外部控制，可在照明應(yīng)用中用于實現(xiàn)調(diào)光功能。