Semtech Debuts Software Controllable Octal LED Driver for Portable Devices.SC620 Provides 800:1 LED Current Dimming Range via I2C I2C Inter-Integrated Circuit I2C Intelligent Interface Controller I2C Intelligent Controller Software Control CAMARILLO, Calif. -- Semtech Corp. (Nasdaq: SMTC SMTC Southern Maine Technical College SMTC Science/Mathematics/Technology Center (Central Michigan University) SMTC Saluda Mountain Telephone Company (Knoxville, Tennessee) SMTC Short-To-Medium Term Control ), a leading supplier of analog and mixed-signal semiconductors for communications, portable devices, computers, and industrial equipment, today announced the SC620, an octal A numbering system that uses eight digits. It is used as a shorthand method for representing binary characters that use six-bits. Each three bits (half a character) is converted into a single octal digit. Okta is Greek for 8. , I2C-controlled LED driver. The SC620 is designed to provide regulated currents for powering a wide range of LEDs, including white, red, blue, green or yellow, with different forward voltages. The SC620 is designed to drive the LED backlights for small to medium size LCDs in portable systems that use rechargeable re·charge tr.v. re·charged, re·charg·ing, re·charg·es To charge again, especially to reenergize a storage battery. re lithium ion/polymer batteries, but may also be applied in systems with a fixed 5V or 3.3V bus. Its low 150mV current sink dropout (1) On magnetic media, a bit that has lost its strength due to a surface defect or recording malfunction. If the bit is in an audio or video file, it might be detected by the error correction circuitry and either corrected or not, but if not, it is often not noticed by the human voltage makes it especially suited for use with LEDs that have forward voltages that are less than the system supply voltage. All LEDs are connected in parallel, with power coming from the system battery or available power rail and each cathode connected to an independent current sink. Up to eight parallel LEDs, or strings of LEDs, can be driven at one time, and each string can be enabled/disabled or dimmed independently using the I2C control bus. Multiple SC620 devices can be connected to the same I2C bus (Inter-IC bus) A two-line bus that is widely used to connect chips together on a printed circuit board. Also called the "I-squared-C bus" and developed by Philips in the 1980s, it is used as a control bus for every variety of chip from sensors to microprocessors. to provide synchronized syn·chro·nize v. syn·chro·nized, syn·chro·niz·ing, syn·chro·niz·es v.intr. 1. To occur at the same time; be simultaneous. 2. To operate in unison. v.tr. 1. control of large banks of LEDs. Each current sink may also be used as an addressable Reachable. When something is addressable, it can be identified and manipulated independently of its surroundings. For example, screen pixels and RAM memory are addressable. Each of the screen's picture elements can be individually turned on and off, and each of the memory's bytes can be general-purpose output, to enable multiple devices or functions remotely using only the two lines for the I2C interface. The current sinks are very accurate and exhibit close matching when programmed for the same current, making them ideal for LCD backlighting back·light n. A type of spotlight, used in photography, that illuminates a subject from behind. tr.v. back·light·ed or back·lit , back·light·ing, back·lights applications. The current setting range allows dimming ratios up to 800:1, excellent for LCD panels Also called a "projection panel," it is a data projector that accepts computer output and displays it on a see-through liquid crystal screen that is placed on top of an overhead projector. See data projector. that are exposed to varying ambient light conditions. The flexibility to select the power source for driving the loads allows for a lower cost solution, or lets the designer select an available source that maximizes efficiency for a particular application. An enable pin allows the system designer to set the part into an ultra-low power shutdown state where the LEDs are disconnected, preventing residual glow due to leakage. The SC620 input voltage range is 2.7V to 5.5V. The maximum total output current capability is 200mA. In a typical application (VBATT=3.6V typ.), eight white LEDs (Vf = 3.4V) can be driven at 25mA each (full brightness) with 92 percent efficiency. "The versatility of this device allows full brightness control to be easily obtained using a reliable two-wire serial interface, only one external component, and an industry proven LED current control topology," said Karl Volk, Director of Marketing for Semtech's Portable Power Management Products Group. "Additional space savings can be accomplished for those who use any remaining SC620 outputs as general purpose controls to power additional devices within the same space-limited system." The ultra-small SC620 features a 3mm x 3mm MLPQ-UT-16 package with a low profile of just 0.6 mm maximum - perfect for small form factor designs. It is RoHS and WEEE WEEE Waste from Electric and Electronic Equipment (directive) WEEE Waste Electrical and Electronics Equipment WEEE Waste Electrical and Electronic Equipment compliant. To assure safe operation across all load conditions, the SC620 contains protection features such as short circuit current limit, thermal protection and under-voltage lockout lockout, intentional closing up of a company, factory, or shop by an employer to prevent employees from working during a strike or labor dispute. The term lockout . Key Features of the SC620 * Eight independently controlled current sinks * 150mV maximum dropout voltage * Current sinks can also be used as general purpose outputs * Very wide output current range: 31.25oA to 25mA * 800:1 current dimming range * Integrated I2C serial bus communication * Drives full array of LEDs, any color combination per string * Low noise solution using only one external ceramic capacitor A Ceramic Capacitoris a capacitor constructed of alternating layers of metal and ceramic, with the ceramic material acting as the dielectric. Depending on the dielectric, whether Class 1 or Class 2, the degree of temperature/capacity dependence varies. Pricing and Availability The SC620 is available immediately in production quantities and is priced at $0.68 each in 1,000-piece lots. Ordering code for the SC620 is SC620ULTRT. Semtech offers comprehensive design assistance, including field- and factory-based support. Data sheets, volume pricing, delivery quotes, as well as evaluation kits and samples, are available by contacting salesinfo@semtech.com. 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 info@semtech.com; or visit its web site at www.semtech.com. Semtech and the Semtech logo are marks of Semtech Corporation. |
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