Hands on the Pulse Width Modulation
Taiwanese design house Richtek has filed a patent
infringement complaint with the US International Trade Commission (ITC) against
uPI Semiconductor, AMD, Sapphire Technology, Diamond
Multimedia and XFX.
The outfit claims that the graphics chip makers have been
nicking their technology related to Pulse Width Modulation. Richtek said that technology involved in the graphics
chip company's portfolios violate its patents No. 7315190, 6414470 and
7132717.
The first patent is for a PWM (Pulse Width Modulation)
circuit, which can get an external programming signal without any extra
pin. The second is a method for current balance in a multi-phase DC-to-DC
converter to produce a respective PWM signal to regulate the
corresponding channel current. The third is for a power metal oxide
semiconductor transistor layout comprising: a gate electrode with a lattice
pattern on a substrate having a first area and a second area. (You lost me at 'the'. sub.ed.)
All heavy technology and probably not something that is
going to grab the headlines.