Semtech 700mA charge pump powers cell phone camera flash

Date Announced: 22 Mar 2006

Tiny SC618 Has Built-In 1X Mode for Spotlight Application and Tightly Regulated Current for Stable LED Flash Output

CAMARILLO, Calif.- Semtech Corp. (Nasdaq:SMTC - News), a leading supplier of analog and mixed-signal semiconductors for communications, portable devices, computers, and industrial equipment, today announced the SC618, a constant-current charge pump for white LEDs that offers innovative protection features for flash applications in cell phones, portable digital assistants (PDAs) and digital cameras.

The SC618 is the first device in Semtech's next-generation charge pump ICs designed to drive and protect high-current LEDs in flash applications. Using only a single setting resistor, the SC618 operates either in flash mode to drive high-intensity bursts of up to 700mA to a flash LED for short durations, or in spotlight (torch) mode to provide lower currents which can be maintained indefinitely. Spotlight mode is set to 40% of flash mode current, permitting the LED to remain on for longer periods of time with less battery draw.

The SC618 delivers an innovative timeout feature designed to shut off the flash output current which, if improperly delivered, can subject the load to potential damage from these extended high current levels. After one second, the SC618 disables the output current in order to safeguard the system against late or missing disable commands contributed from faulty software or system malfunction. This timeout function is part of a comprehensive protection feature set, including input over-voltage protection, output over-voltage protection, over-temperature protection, short circuit protection and soft start functionality.

The SC618 provides a tightly regulated current level with minimum and maximum output current varying by only 8% over its full range of input voltage and temperature to deliver the stable light source needed for high-quality photos. In flash mode, the device can output 700mA for up to 350 milliseconds or 500mA for 500 milliseconds with tight current regulation during the entire flash event.

"As the emerging 3G and Smart phone makers embrace high current LED flash in their systems for high quality pictures, the SC618 addresses the system requirements for high current flash with innovative features such as the safety timer," said Ven Shan, Vice President of Marketing for Semtech's Power Management Products. "The combination of this protection, the 1X spotlight mode and the current regulation performance makes the SC618 the most optimized charge pump for flash applications."

The SC618 is offered in a 3 mm x 3mm MLPD-UT-10 lead-less package with only a 0.6 mm profile and can be used in the slimmest and smallest of handheld devices. The highly integrated nature of the SC618 provides a complete flash power solution that can be implemented with only the SC618, an LED and five other components, thereby reducing costs and consuming less board space.

Key Features of the SC618

* Built-in 1-second safety timer
* 1X spotlight mode operation
* Input over-voltage protection: device is disabled if input voltage is greater than 6V
* Output over-voltage protection: device is disabled if output voltage is greater than 5.5V
* Over-temperature protection: device is disabled when junction temperature exceeds 150 degrees C
* Over-current protection: prevents device overheating when sourcing maximum current to the load
* Short-circuit current protection: Device detects a short to ground when output voltage drops below 2V and limits the output current
* Low EMI operation: capacitor-based solution, requiring only two small bucket capacitors to develop the output drive, provides advantage over inductive-based solutions
* Low profile, lead-free package is RoHS/WEEE compliant

Pricing and Availability

The SC618 is available immediately in production quantities and is priced at $1.45 each in 10,000-piece lots. Semtech offers comprehensive design assistance, including field- and factory-based support. The ordering code for the part is SC618ULTRT. Data sheets, volume pricing, and delivery quotes, as well as evaluation kits and samples, are available by contacting

About Semtech

Semtech Corporation is a leading supplier of high-quality analog and mixed-signal semiconductor products. The company is dedicated to providing customers with proprietary solutions and breakthrough technology in power management, protection, advanced communications, human interface, test & measurement, and wireless connectivity products. Publicly traded since 1967, Semtech is listed on the NASDAQ National Market under the symbol SMTC. For more information, contact Semtech Corp. at 200 Flynn Road, Camarillo, CA 93012-8790; phone (805) 498-2111; email to; or visit its web site at

Semtech Corporation Terry Sears, 805-480-2052

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