摘要:
A quadrature voltage controlled oscillator having low phase noise and excellent output swing characteristics includes a first voltage controlled oscillator for outputting a positive in-phase output signal and a negative in-phase output signal; a second voltage controlled oscillator for outputting a positive quadrature-phase output signal and a negative quadrature-phase output signal, the second voltage controlled oscillator having a symmetrical structure with the first voltage controlled oscillator and constituting a feedback loop together with the first voltage controlled oscillator; a first constant current source for supplying constant current to the first voltage controlled oscillator in response to the output signals; and a second constant current source for supplying constant current to the second voltage controlled oscillator in response to the output signals.
摘要:
A scheme to reduce output variations in a column driver for a flat-panel display by sharing the characteristics of analog circuit is disclosed. An input multiplexer is provided between two neighboring digital inputs, and an output multiplexer is provided between two neighboring analog outputs so that the characteristics of neighboring analog circuits can be shared by multiplexing. The averaging effect by sharing reduces variations in the output. The multiplexing may be done either in time division or on a frame-by-frame basis.
摘要:
A radio communication apparatus and a frequency generating method thereof the communication apparatus including a frequency generator to generate a plurality of local oscillator (LO) frequencies; and a mixer to convert a frequency of an input signal by mixing the input signal with at least two of the LO frequencies generated by the frequency generator. As the LO frequencies are generated using the single VCO to support the radio communication standard of the multiple bands, the circuit area can be reduced and the multimode and multiband can be supported with one chip.
摘要:
An organic light-emitting diode display driver adjusts the display scan period of the current driving the organic light-emitting diodes of a selected row based upon the sum of the display data corresponding to the selected row, thereby removing crosstalk in the OLED display panel. The driver includes an adder for adding the display data corresponding to the selected row and a scan period look-up table storing display scan period values. The scan period look-up table is configured such that it outputs display scan period values substantially proportional or inversely proportional to the sum of the display data to remove bright crosstalk or dark crosstalk, respectively, in the OLED display panel.
摘要:
A quadrature voltage controlled oscillator having low phase noise and excellent output swing characteristics includes a first voltage controlled oscillator for outputting a positive in-phase output signal and a negative in-phase output signal; a second voltage controlled oscillator for outputting a positive quadrature-phase output signal and a negative quadrature-phase output signal, the second voltage controlled oscillator having a symmetrical structure with the first voltage controlled oscillator and constituting a feedback loop together with the first voltage controlled oscillator; a first constant current source for supplying constant current to the first voltage controlled oscillator in response to the output signals; and a second constant current source for supplying constant current to the second voltage controlled oscillator in response to the output signals.
摘要:
An integrated graphic and character combining circuit for driving a display device, for example an LCD panel, allows for a configuration by which an external ROM is not necessary, reduces processing burden on the data-supplying processor, and provides a system wherein both graphic images and complete character fonts can be combined and simultaneously displayed on an LCD panel. The circuit includes a character font ROM, a character display data RAM, a graphic image data RAM, a property register, a character/graphic mixed display control circuit, an interface circuit, and a common/segment LCD driver. The character font ROM stores font data pertaining to complete characters. The character display data RAM stores addresses corresponding to the font data stored in the character font ROM. The graphic image data RAM stores graphic image data. The property register stores selection information pertaining to the graphic and character data. The character/graphic mixed display control circuit receives the font data from the character font ROM and graphic image data from the graphic image data RAM, and selects and outputs final data to be displayed on an LCD panel, in response to the output of the property register.