ST breaks through LED camera flash limitations

GENEVA, SWITZERLAND: An innovative IC from STMicroelectronics will enable compact digital cameras and cameraphones to satisfy demands for increased power from the built-in flash unit while supporting more sophisticated user controls.

ST’s new chip, the STCF04, is an integrated camera flash and torch controller that raises the maximum power of an LED flash module from a few Watts, typical of today’s designs, to over 40 Watts, producing the brightness equivalent to an outdoor security floodlight. The new device also provides extra flash and torch brightness controls, with eight user-selectable levels for the flash and 12 for the torch, as well as a light-sensor input. Flash and torch safety timers, temperature sensing and short-circuit protection features are also built in.

The STCF04 is used in a unique configuration combining a supercapacitor, a discrete high-current MOSFET switch and high-power white LEDs, and is ideal for use in emergency high-intensity flashing lights as well as camera and cameraphone applications.

The discrete MOSFET is the key to the STCF04’s power advantage over other controllers that usually integrate a MOSFET of lower rating on the chip. Its extra power enables designers to provide the higher quantities of light energy required by today’s high-Mpixel camera sensors by specifying an LED flash unit rather than a conventional high-power xenon flash, thereby gaining the advantage of a compact and simplified design.

Since ST began sampling the STCF04, two major partners – Murata which is leading producer of supercapacitors (MURATA) and OSRAM which is a top-tier supplier of flash modules for leading smartphone platforms have begun using the device to showcase the best capabilities of their latest products.

Major features of STCF04:
• Maximum flash power >40W.
• 1 x 320mA torch current.
• 100mA privacy indicator red LED output; 12 adjustment steps.
• I2C bus with selectable address.
• Temperature sensing, short-circuit, over-voltage and flash/torch timer safety features.

Available in the 25-bump 3 x 3mm TFBGA package, the STCF04 is currently sampling. Full production is planned at the end of Q1 2012 priced at $2.00 for orders of 1,000 pieces. Alternative pricing options may be available for higher quantities.