Linear Technology's LT3468ES5: A Compact, Integrated Photoflash Capacitor Charger

The LT3468ES5 is a highly efficient, integrated solution designed by Linear Technology for charging photoflash capacitors in digital and film cameras. This compact, feature-rich component is engineered to simplify the design of portable photography equipment by providing a quick and efficient charging solution for high-voltage photoflash capacitors.

Key Features and Benefits

• Integrated Power Switch: The LT3468ES5 includes an internal high-voltage N-channel MOSFET power switch, which enhances efficiency and reduces external component count, leading to a more compact design.
• Adjustable Charging Current: Designers can set the charging current to a desired level using a single external resistor, providing flexibility to accommodate various capacitor sizes and optimize charge times.
• Primary-Side Current Sensing: This feature eliminates the need for a power-consuming sense resistor on the high-voltage side, further improving efficiency and reducing overall power consumption.
• Constant Current/Constant Voltage (CC/CV) Operation: The LT3468ES5 operates in constant current mode for the bulk of the charging cycle, switching to constant voltage mode as the capacitor approaches full charge, ensuring a full and efficient charge cycle.
• Automatic Refresh Charge: The device periodically applies a refresh charge to the capacitor to keep it fully charged without overcharging, which is critical for maintaining the longevity and reliability of the photoflash capacitor.
• Low Quiescent Current: With a quiescent current of only 120µA, the LT3468ES5 minimizes battery drain when the flash is not in use, making it ideal for battery-powered devices.
• Thermal Protection: Built-in thermal shutdown protects the device from overheating, ensuring safe operation under varying environmental conditions.

Applications

The LT3468ES5 is suitable for a wide range of applications beyond digital and film cameras, including portable medical devices, industrial measurement equipment, and any portable device that requires a high-voltage photoflash capacitor charging solution. Its small footprint and ease of integration make it a popular choice for designers looking to enhance the performance of their portable devices without sacrificing space or battery life.

With the LT3468ES5, Linear Technology demonstrates its commitment to providing innovative, space-saving, and power-efficient solutions for the ever-evolving portable electronics market.