An SoC With 1.3 Gtexels/s 3-D Graphics Full Pipeline for Consumer Applications

A novel on-chip step-dimmer for low cost AC-powered HV-LED driver

“…Secondly, the power (in Watts) of the works can be customized in the design process without changing the performance of the circuits. For instance, to increase the power in this work, either the dimming voltage can be Table I, the proposed design can gain a very high PF and a low THD as compared with the non-dimmable designs in [1,2,3]. In comparison with the dimmable AC LED driver reported in [4], the proposed design owns the similar performance with a more simple circuit structure.…”

“…Recently, various non-isolated AC-powered LED drivers with multiple LED strings have been introduced, enabling a high power factor (PF), a low total harmonic distortion (THD) as well as lows crest factor [1,2,3]. However, the dimming function which is important for a light source that the luminance can be adjusted is not available on these AC LED drivers.…”

An 8M Polygons/s 3-D Graphics SoC With Full Hardware Geometric and Rendering Engine for Mobile Applications

“…We choose the fully hardware pipelined 3DG accelerator for low power consumption. To support various applications and utilize the advantages of SoC [3], we integrated the ARM9 reduced instruction set computer (RSIC) core, dual SDRAM controller and CPMU. The CPMU supports several operation modes: "normal mode," "3DG application mode," "3DG acceleration mode," and "bypass mode.…”

Multi-string AC-powered LED driver with current regulation reduction based on simple circuitry

“…Most of them use a bulky transformer and electrolytic capacitors which shorts the lifetime of LED module and cannot be integrated inside the chip. Then, some researchers have been trying to design AC directly-controlled LED drivers which eliminate totally transformer and electrolytic capacitors [5,6]. In the design presented in [5], the design gains a high PF and improves THD; however, it may results in a current glitch due to hard switching operation that degrades the THD due to severe current distortion which then degrade PF [1].…”

“…In the design presented in [5], the design gains a high PF and improves THD; however, it may results in a current glitch due to hard switching operation that degrades the THD due to severe current distortion which then degrade PF [1]. With the design in [6], although the glitch phenomenon is eliminated due to the use of a soft-switching mechanism, it owns another shortcoming of the change of reference voltage level if the input voltage changes. In other hand, at the workplaces where the ac power supply is unstable (without using stabilizers) the fluctuation of the input voltage may cause the variation of LED brightness, shorten the LED lifetime or even damage LED bubs in case of the overvoltage rating conditions.…”