Patent application number | Description | Published |
20090167264 | DC-DC CONVERTER USABLE FOR DUAL VOLTAGE SUPPLY - A converter has a single inductor with a first terminal connectable to a first terminal of the supply input through a first power transistor and a second terminal connectable to a second terminal of the supply input through a second power transistor. A first rectifier element connects the first terminal of the inductor with a first output terminal, and a second rectifier element connects the second terminal of the inductor with a second output terminal. A resistive voltage divider is connected between the first and second output terminals. A control circuit uses an input from the voltage divider as a reference input voltage and provides an output current to the second terminal of the supply input in response to any voltage difference between the reference input voltage and the second terminal of the supply input. This provides a virtual common reference potential at the second terminal of the supply input, which is thus a common ground (GND) terminal. In the ON phase of both power transistors, the inductor is charged with current from the supply input. In the OFF phase (both power transistors are OFF), the energy stored in the inductor is supplied to both of the positive and the negative supply output through the rectifier elements, the output current in fact flowing almost exclusively between the positive and negative supply outputs. Thus, in the OFF phase, the inductor is entirely isolated from the supply input and the supply outputs are in no way affected by any transients or fluctuations in the supply input voltage. | 07-02-2009 |
20110193839 | LEVEL SHIFTER FOR USE IN LCD DISPLAY APPLICATIONS - A level shifter for use in LCD display applications is provided which includes a group of separate channels each with a signal input and a signal output and with channel control circuitry supporting gate voltage shaping for improving image quality. The level shifter further has a number of flicker clock inputs. The channel control circuitry of each particular channel in the group comprises logic circuitry combining all of said flicker clock inputs with the signal input of the particular channel and signal inputs form other channels into a gate voltage shaping enable signal for the control circuitry of the particular channel. With this configuration it is possible to use the same level shifter IC with only one flicker clock signal for all phases, regardless of how many, without the need for an additional synchronization signal, or multiple flicker clock signals as is conventional. The level shifter automatically determines which input signal needs to be modified for the gate voltage shaping when the active portion of the flicker clock signal is detected. | 08-11-2011 |
20130113540 | ELECTRONIC DEVICE AND METHOD FOR PROVIDING A DIGITAL SIGNAL AT A LEVEL SHIFTER OUTPUT - An electronic device comprising a level shifter and a method. The level shifter includes an input adapted to receive an input signal switching between a low input voltage level and a high input voltage level and a first switch and a second switch coupled in series between a low output voltage supply and a high output voltage supply. An output is coupled to an interconnection node between the first and the second switch and is adapted to be coupled to a load. The first and second switches are controlled by the input signal. The level shifter further includes a third switch which is coupled between the interconnection node and an auxiliary voltage supply which has a voltage level between the low output voltage level and the high output voltage level. | 05-09-2013 |