This short little app note with a long title discusses the LT3468, which is a monolithic power-converter chip for driving camera flashtubes. As Figure 1 testifies, flashlamps are much brighter with better color temperature than LEDs, and so are the preferred illuminator for digital cameras. After a brief discussion of the physics, Jim discusses the support circuitry and construction requirements. "Capacitor, wiring and lamp impedances typically total a few ohms, resulting in transient current flow in the 100A range."
This app note contains a single application schematic, shown in Figure 6. Most of the text is dedicated to measurements of the circuit performance (Figures 7 to 10). Figures 9 and 10 are particularly interesting, with vertical scales of "relative light per division". Surprisingly, Jim does not reveal how he made the "relative light" measurements.
A carefully worded caution appears near the end of the text:
In cases where the lamp is triggered with a user-selected transformer and drive scheme, it is essential to obtain lamp vendor approval before going to production.That quote sounds like the voice of unfortunate experience.
The app note ends with a cartoon. "Nice seeing you again. Yeah, nice seeing you again, too."
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