Semtech Advances Highly Efficient, Low-Voltage Synchronous Step-Down ControllerDrawing from 2.7V to 6V, the highly integrated, feature-rich SC4601 switched controller supplies outputs from 5V down to 0.8V while saving board space and cutting costs Camarillo, California - April 01, 2003 Semtech Corp. (NASDAQ: SMTC), a leading supplier of analog and mixed-signal semiconductors for communications, portable devices, computers, and industrial equipment, today announced a highly efficient, low-voltage controller for building synchronous step-down ("buck") switch-mode regulators. The highly integrated, BiCMOS-based SC4601 controller is designed to drive two external, complementary power MOSFETs.
Geared for the latest low-voltage designs, the SC4601 supplies 5V to 0.8V from a 2.7V to 6V source. Some specific applications for the SC4601 include distributed (point-of-load) power architectures; servers and workstations; microprocessor-core, DSP, and I/O power supplies; and battery-powered, telecommunications, and data communications equipment. The SC4601 expands Semtech’s portfolio of networking and industrial switching controllers with a highly integrated, high efficiency, low-voltage, small footprint, synchronous buck device,” notes George Georgalis, Semtech’s Director of Networking/Industrial Power Management. “System and power-supply designers who compare it with competitive parts will find the SC4601 hard or impossible to beat, given its broad array of features and benefits.” The SC4601 drives two external complementary power MOSFETs: a P-channel MOSFET on the high side and, on the low side, its N-channel counterpart. Having a high-side P-channel MOSFET kills the need for an external charge pump and simplifies the high-side gate-drive circuit. In addition, built-in nonoverlap protection prevents both MOSFETs from conducting simultaneously and causing current to shoot through both of them. Also, during conduction, the SC4601 senses the voltage drop across the P-channel MOSFET to impose lossless current limiting in the event of a short circuit. For enhanced power efficiency, the SC4601 can drop into a sleep mode, which typically draws only 10 µA. Moreover, the SC4601’s switching frequency can be synchronized to an external oscillator of up to 700 kHz. Also, soft-start operation, spread over a 5-ms period, prevents output voltage spikes during start-up. Still other key features include a duty cycle that is programmable from 0 to 100 percent. This feature, and in particular the ability to set the duty cycle to 100 percent, allows the SC4601, in the event of a low battery, to operate as a low-dropout (LDO) voltage regulator. Voltage accuracy is maintained by the SC4601’s built in ±1 percent accurate 0.8V (typical) reference. Key Features of the SC4601
Pricing and AvailabilityProduction volumes of the SC4601 controller are available now through Semtech's authorized network of sales representatives and distributors. The product comes in an MSOP-10 package and operates over a –40° to +85°C temperature range. Pricing starts at $0.81 each in 10,000-piece quantities. Datasheets are available at www.semtech.com. About SemtechSemtech 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 and measurement, and high-speed clock/logic 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, CA93012-8790; phone (805) 498-2111; email to info@semtech.com; or visit its web site at www.semtech.com. Press ContactTerry Sears, Marketing Communications Manager, Telephone: 805.498.2111 |
Among the SC4601’s many competitive features are its efficient, accurate, low-voltage operation; low-current sleep mode; lossless overcurrent protection; programmable switching frequency to 700 kHz; soft-start operation; 0 to 100 percent duty cycle; and a small surface-mount package. By packing all this capability into the outline of a 10-lead MSOP, the SC4601 reduces the size and cost of building low-voltage power sources. And by reducing the parts count, the SC4601 streamlines component procurement and end-equipment manufacturing.
