The CAT3644 is a high efficiency Quad-Mode® fractional charge pump that can drive up to four 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 use of small external ceramic capacitors. The multi-fractional charge pump supports a wide range of input voltages from 2.5V to 5.5V. The EN/DIM logic input functions as a chip enable and a digital dimming interface for
The CAT3644 is a 4‑channel ultra‑high‑efficiency quad‑mode LED driver from Catalyst Semiconductor. It supports up to four LEDs, offers multiple charge‑pump ratios (1x, 1.33x, 1.5x, 2x) and provides a one‑wire EZDim™ programming interface for precise current control.
The document provides complete electrical specifications, absolute maximum ratings, recommended operating conditions, pin descriptions, typical performance curves, and ordering information for the 3 mm × 3 mm 16‑pad TQFN package.
| Input voltage range | 2.5 V to 5.5 V |
|---|---|
| LED forward voltage range | 1.3 V to 4.3 V |
| Power efficiency | up to 92 % |
| Package | 3 mm × 3 mm 16‑pad TQFN |
| Thermal shutdown temperature | 150 °C |
| Storage temperature range | -65 °C to +160 °C |
The CAT3644 operates with an input voltage from 2.5 V to 5.5 V.
It can drive up to four LEDs, each at 25 mA.
LED current is programmed via a one‑wire EZDim™ digital dimming interface (EN/DIM pin).
The device is supplied in a 3 mm × 3 mm 16‑pad TQFN package.