GENERAL DESCRIPTION
LM3550 features user selectable super-capacitor charge termination voltages and an optimal charge termination mode that maximizes flash energy efficiency by accounting for flash element losses. Additionally, the device provides one adjustable constant-current output (up to 200mA) and one NFET controller ideal for driving one or more high current LEDs either in a high power Flash mode or a low power Torch mode. Optimal Charge mode adapts to changes in the flash LEDs forward voltage as well as the supercapacitor's ESR ensuring that the super-capacitor is charged to the ideal voltage required to sustain constant current flash operation. The Strobe pin allows the Flash to be toggled via a Flash enable signal from a camera module. The EOC pin sinks current when the output voltage reaches 95% of the final value. The ALD/TEMP input pin allows either a light sensor to adjust the flash current level based on the ambient light conditions, or it allows for over-temperature det...
National Semiconductor
