Milpetas,CA Linear Technology introduces the LTC3783 , a current-mode multi-topology converter with constant-current PWM, dimming for driving high-power LED strings and clusters. Proprietary techniques provide extremely fast, true PWM load switching with no transient undervoltage or overvoltage issues. Ratios of 3000:1 can be achieved digitally as True Color PWM dimming guarantees colour integrity of white and RGB LEDs. The LTC3783 allows an additional 100:1 dimming ratio using analogue control. This versatile controller can be used as a boost, buck, buck-boost, SEPIC, or flyback converter, and as a constant-current/constant-voltage regulator. No RSENSE operation uses the on-resistance of a MOSFET to eliminate the current-sense resistor, increasing efficiency. Applications for the LTC3783 include high-voltage LED arrays and backlighting, as well as voltage regulators in telecom, automotive and industrial control systems. The LTC3783 operates from input supplies ranging from 3 V to 36 V and provides overvoltage protection while regulating output current. Integrated drivers for power and load MOSFET switches and an adjustable feedback voltage (0 V to 1.23 V) make this part especially convenient for higher-power LED lighting applications. One resistor sets operating frequency from 20 kHz to 1 MHz. Moreover, to reduce switching noise interference, the LTC3783 is synchronizable to an external clock. Programmable soft-start limits inrush current during startup, preventing input current spikes. The LTC3783 is rated for operation from -40°C to 85°C with a maximum junction temperature of 125°C. It is offered in 16-lead 5 x 4mm DFN and TSSOP packages. 1,000-piece pricing starts at $2.85 each. Linear Technology Ltd , Milpetas,CA. www.linear.com.
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.