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

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™ 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

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 info@semtech.com.