Semtech Introduces the SC1464 Charge-Pump DoublerJanuary 16, 2000 by Jeff Shepard
Semtech Corp. (Newbury Park, CA) recently announced the availability of the SC1464, a 60mA charge-pump doubler that is designed to provide a simple-to-implement boost solution for portable applications. Semtech claims the SC1464 helps designers reduce complexity and cost by eliminating the inductor typically used in switcher-based designs.
The SC1464 is designed to provide a double output from a 2.5V to 3.5V input supply. The device is designed with four user-selectable oscillator frequencies (8kHz, 32kHz, 260kHz and 1MHz) that are designed to offer flexibility to optimize capacitor selection for size, supply current and efficiency considerations, as well as prevent interference with sensitive surrounding circuitry.
The SC1464 is also designed to operate over the full industrial temperature range (-40 degrees to +85 degrees C). A typical 20mA application requires only 1uF for the input and output capacitor and 0.22uF for the bucket capacitor, while providing better than 94 percent efficiency at a 260kHz oscillator frequency. According to the company, voltage dropout is less than 50mV at full load. Other features of the device include an enable pin, soft-start functionality, and short-circuit and over-temperature protection.
"Designers currently using switcher-based designs will benefit from the elimination of an inductor, both in terms of cost reduction and board space savings," said Jon Horner, product marketing engineer for Portable System Products, Semtech Corp. "Only three tiny surface-mount capacitors are required; combined with the small MSOP-8 package this translates into an extremely small total-solution size. Finally, the SC1464 draws less than 1uA under shutdown, helping to extend battery life in portable applications." Horner concluded, "Semtech's introduction of the SC1464 helps designers of hand-held wireless products in three very important areas: cost, size and battery life." Samples of the SC1464 are available in MSOP-8 packaging with full production units available in February 2000. In quantities of 1,000, pricing for the SC1464 is $1.43 each.