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Charge Pump Drivers enhance LED backlighting in handhelds.

Press Release Summary:

Supplied in 2 x 2 x 0.6 mm plastic package, models SC654, SC657, and SC658 drive 6, 5, and 4 LEDs, respectively. Integrated mAhXLife(TM) charge pump monitors each LED's forward voltage and automatically selects 1x, 1.5x, or 2x mode to optimize efficiency. Also included, low-dropout current sink regulators provide LED current matching of 0.5% typ. LED current may be adjusted from 0-25 mA in 29 settings via one-wire SemPulse® interface, which also controls various other functions.

Original Press Release:

Semtech Announces New Platform of Tiny Charge Pumps for LED Backlighting in Handheld Devices

SC654, SC657, SC658 fit in 2x2mm ultra-thin plastic package and drive 6, 5, 4 LEDs, respectively, using one-wire SemPulse® digital interface

Camarillo, California - October 20, 2009
Semtech Corp. (Nasdaq: SMTC), a leading supplier of analog and mixed-signal semiconductors, today announced the SC654, SC657 and SC658 LED backlight charge pump drivers for 6, 5, and 4 LEDs, respectively. Optimized for single-cell Li-ion battery applications, each part in this new platform is packaged in ultra-thin (0.6mm max.) 14-pin 2x2mm MLPQ package to provide the industry's smallest solution in reliable and easy-to-handle plastic packaging.

Each member of the SC65x platform integrates a high-efficiency charge pump, multiple low-dropout current sink regulators, and the proprietary one-wire SemPulse® interface. The mAhXLife(TM) charge pump monitors each LED's forward voltage and automatically selects between 1x, 1.5x and 2x modes to optimize efficiency as the battery voltage changes over time. The low-dropout current sink regulators provide LED current matching of 0.5% typical to ensure accurate and even illumination. LED current may be adjusted from 0mA to 25mA in 29 settings via the one-wire SemPulse® interface. In addition, the SemPulse® interface controls many other functions, including chip enable/shutdown, individual on/off for each current sink, up to three zones of lighting with individual current settings for each bank of LEDs, and three optional fade-in/out rates for elegant transitions when changing current settings.

In many modern handheld systems, the usual I²C serial bus is becoming over-burdened with too many slave ICs. In such cases, the SemPulse® interface is highly preferred because it provides a simple means of programming many features while consuming only one GPIO on the baseband or applications/graphics processor. The interface is simple, robust, and very tolerant of sloppy timing caused by interrupts elsewhere in the system. Semtech's applications team provides full design-in support with sample code and pre-written drivers to minimize the customer's software development efforts.

"The SC654, SC657, and SC658 are perfectly optimized to power backlights in next-generation mobile handheld applications where size is the key factor," said Karl Volk, Semtech Director of Marketing for Handheld Power. "This new platform sets the benchmark for its performance and sophisticated features within a tiny, thin and reliable footprint, thereby increasing value to our customers."

The SC654, SC657, and SC658 are available in 2x2mm lead-free 14-pin MLPQ-UT package, are halogen-free, and comply with the European Union's Restriction on Hazardous Substances in Electrical and Electronic Equipment (RoHS) directive to meet worldwide environmental and regulatory requirements

  • Input supply voltage range - 2.9V to 5.5V
  • Charge pump modes - 1x, 1.5x and 2x
  • Six (SC654), five (SC657) or four (SC658) adjustable current sinks
  • One-wire SemPulse® interface
  • 29 current settings from 0 to 25mA
  • Current accuracy ±1.5% typical
  • Current matching ±0.5% typical
  • Individual on/off control for each LED
  • Up to three zones/banks of LED current settings
  • Optional fade-in/out with three programmable rates
  • Ultra-thin MLPQ package - 2 x 2 x 0.6 mm

    The SC654 (Order code: SC654ULTRT) is priced at $0.60 each in 3,000-piece lots. The SC657 (Order code: SC657ULTRT) is priced at $0.55 each in 3,000-piece lots. The SC658 (Order code: SC658ULTRT) is priced at $0.51 each in 3,000-piece lots. Each device is available immediately in production quantities. Evaluation boards (SC654EVB, SC657EVB, and SC658EVB) are also available. Semtech offers comprehensive design assistance, including field- and factory-based support. Data sheets, volume pricing, and delivery quotes, as well as evaluation kits and samples, are available by contacting

    Semtech Corporation is a leading supplier of analog and mixed-signal semiconductors for high-end consumer, computing, communications and industrial equipment. Products are designed to benefit the engineering community as well as the global community. The company is dedicated to reducing the impact it, and its products, have on the environment. Internal green programs seek to reduce waste through material and manufacturing control, use of green technology and designing for resource reduction. Publicly traded since 1967, Semtech is listed on the NASDAQ Global Select Market under the symbol SMTC. For more information, visit

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