The CAT3643 is a high efficiency Quad-Mode® fractional charge pump that can drive up to three LEDs programmable by a one wire digital interface. The inclusion of a 1.33x fractional charge pump mode increases 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 device to provide up to 92% power efficiency in any mode.
The CAT3643 LED driver offers four charge‑pump modes (1×, 1.33×, 1.5×, 2×) and can drive up to three LEDs at 32 mA each. It features 1‑wire EZDim™ programming, low‑noise input ripple, soft‑start, current limiting, short‑circuit and thermal shutdown protection, and is available in tiny 12‑pad XQFN, 12‑pad TDFN and 16‑pad TQFN packages.
The datasheet provides absolute maximum ratings, recommended operating conditions, electrical characteristics, timing diagrams, typical performance curves, and ordering information for the various package options. Revision history and trademark notices are also included.
| Efficiency | up to 92% |
|---|---|
| Input Voltage Range | 2.5 V to 5.5 V |
| LED Current per Pin | up to 30 mA |
| Maximum LED Count | 3 LEDs |
| Thermal Shutdown Temperature | 150 °C |
| Package Types | 12‑pad XQFN, 12‑pad TDFN, 16‑pad TQFN |
The device operates with an input voltage from 2.5 V to 5.5 V.
It can drive up to three LEDs, each at up to 32 mA.
The driver achieves up to 92 % power efficiency.