Synaptics Corporation

Brian Mott

Imre Knausz

Eric Scott Bohannon

Clyde Washburn

John Childs

A voltage drive circuit is constructed by stacking NMOS and PMOS transistors to provide high voltage levels with an output voltage swing greater than the breakdown voltage of the individual transistors used to build the voltage drive circuit. The voltage drive circuit may include a series stack of capacitors connected between gates of the stacked PMOS and NMOS transistors. The capacitive loading causes the gate signals to change more synchronously. Errors in timing for these gate signals, which would otherwise result in damage from exceeding the breakdown voltage across a pair of terminals of one of the NMOS and PMOS transistors, are mollified.

High voltage driver using medium voltage devices

Embodiments of the invention generally provide an input device that includes one or more source drivers that are coupled to a display screen. Specifically, one of the source drivers may be coupled to a plurality of source lines (or column lines) on the display screen which the source driver uses to set voltages associated with one or more sub-pixels that determine the color displayed by the pixel. When driving voltages onto subsequent source lines, the input device may precharge the source driver using a latent voltage stored on the source lines. That is, if the source line was previously driven to a particular voltage by the source driver, the input device uses that latent voltage to precharge the output of the source driver to the same voltage. The source driver may then adjust its output to a desired voltage and drive the desired voltage onto the source line and sub-pixel.

Method and circuit to optimize N-line LCD power consumption

Embodiments of the invention generally provide generating a ZTC current using resistors that may be integrated into an IC, even if these resistors vary with temperature. Specifically, instead of applying a bandgap voltage across a ZTC resistor, the bandgap voltage may be applied to a temperature-dependent resistor to generate a first current that varies (either proportionally or complementary) with temperature. Additionally, a second current may be generated which compensates for the temperature variance of the first current. If the two currents change in the same manner relative to temperature (i.e., the respective slopes of the currents are the same when the underlying circuit elements are exposed to the same temperature variations), the difference between the currents remains constant. Thus, subtracting the two currents, regardless of the current temperature, results in a ZTC current&#x2014;i.e., a current that is independent of temperature variations.

Growing community of inventors

Rochester, NY, United States of America

Brian Mott