CAT3643 3-Channel Ultra High Efficiency LED Driver Description The CAT3643 is a high efficiency fractional charge pump that can drive up to three LEDs programmable by a one wire digital interface. CAT3643 1 F 1 F C1+ C1 C2+ C2 V V IN OUT V V IN OUT C C IN OUT 2.4 V to CAT3643 1 F 1 F 5.5 V 1Wire EN/DIM LED1 EZDim 20 mA Programming LED2 RSET LED3 4.02 k GND Figure 1. Typical Application Circuit 1 LED1 GND 1 LED2 C2 LED2 C2+ LED3 C2+ LED3 C2 RSET C1 C1 NC EN/DIM C1+ RSET C1+ VOUT VIN TDFN12 TQFN16 Figure 2. Pin Configurations (Top Views) The CAT3643 is offered in three different packages. The 12pad TDFN 3 mm x 3 mm with a max height of 0.8 mm is pincompatible to the ON Semiconductor CAT3603 LED driver. The 16pad TQFN 3 mm x 3 mm with max height of 0.8 mm is also offered. Table 1. ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit V , LEDx, C1, C2, EN/DIM, RSET voltage 6 V IN V voltage 7 V OUT Storage Temperature Range 65 to +160 C Junction Temperature Range 40 to +150 C Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. Table 2. RECOMMENDED OPERATING CONDITIONS Parameter Rating Unit V 2.5 to 5.5 V IN Ambient Temperature Range 40 to +85 C I per LED pin up to 30 mA LED LED Forward Voltage Range 1.3 to 4.3 V Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability. NOTE: Typical application circuit with external components is shown above.