Controllable delays in multiple synchronized signals for reduced electromagnetic interference at peak frequencies
Granted: November 7, 2000
Patent Number:
6144242
Multiple controllable delays reduce EMI radiated during the transmission of multiple synchronized signals. Each controllable delay introduces a controlled delay into a corresponding signal being transmitted. The controlled delay is such that the combined strength of the multiple signals at peak frequencies is substantially reduced. This results in reduced EMI radiation at those peak frequencies.
High density column drivers for an active matrix display
Granted: August 8, 2000
Patent Number:
6100868
To reduce the layout area required by LCD column drivers without suffering a significant decrease in performance, a PMOS-based circuit selects a voltage from an upper set of analog display voltages and a NMOS-based circuit selects a voltage from a lower set of analog display voltages. This reduces the layout area by up to roughly a factor of two compared with conventional column drivers which are CMOS-based. Moreover, in a typical dot inversion scheme, where two adjacent columns select…
System and method for controlling an active matrix display
Granted: August 8, 2000
Patent Number:
6100879
A smart controller chip for controlling an active matrix display. Within the controller chip, circuitry for generating analog reference levels is incorporated alongside circuitry for generating digital timing and control signals. The combination of D/A analog circuitry and standard digital logic makes the controller uniquely suited for addressing all the panel control needs both for the normal digital functions but also for control of the analog aspects of the panel, like display gamma.…
Transition-controlled digital encoding and signal transmission system
Granted: February 15, 2000
Patent Number:
6026124
A method and apparatus for producing a transition-controlled, DC-balanced sequence of characters from an input sequence of data bytes is disclosed herein. The bits in each of the data bytes are selectively complemented in accordance with the number of logical `1` signals in each data byte in order to produce selectively complemented data blocks. A cumulative disparity is then determined between the logical values of different type included within ones of the selectively complemented data…
Transition-controlled digital encoding and signal transmission system
Granted: December 7, 1999
Patent Number:
5999571
A method and apparatus for producing a transition-controlled, DC-balanced sequence of characters from an input sequence of data bytes is disclosed herein. The bits in each of the data bytes are selectively complemented in accordance with the number of logical transitions in each data byte in order to produce selectively complemented data blocks. A cumulative disparity is then determined between the logical values of different type included within ones of the selectively complemented data…
System for high speed serial video signal transmission using DC-balanced coding
Granted: October 26, 1999
Patent Number:
5974464
A new high-speed digital interface for transmitting video information over various transmission media including terminated copper wires such as twisted-pair wires and fiber optical cable is described. The significance of this new interface is that (1) it only uses a small number of data channels with all timing and control data embedded in data transmission, (2) it uses a transition controlled binary DC balanced coding for reliable, low-power and high-speed data transmission, (3) it uses…
Dual loop delay-locked loop
Granted: October 19, 1999
Patent Number:
5969552
A device and method for synchronizing a local clock to a reference clock. The device uses a frequency acquisition loop and a phase acquisition loop. The frequency acquisition loop delays the reference clock to produce an intermediate clock which falls within the operating range of the phase acquisition loop. The phase acquisition loop then delays the intermediate clock to produce a local clock synchronized to the reference clock.
Voltage-controlled oscillator resistant to supply voltage noise
Granted: September 21, 1999
Patent Number:
5955929
A voltage-controlled oscillator (VCO) generates an oscillating signal that is substantially resistant to noise fluctuations in the supply voltage. The VCO is a delay-based VCO which preferably includes a compensation circuit for each delay cell and a noise-immune reference current generator for providing a noise-immune bias current to the conditioning circuit of the VCO. The compensation circuit preferably adjusts the capacitance of the delay cell to compensate for the variations in…
System and method for high-speed skew-insensitive multi-channel data transmission
Granted: May 18, 1999
Patent Number:
5905769
A method and apparatus is disclosed that receives a multi-channel digital serial encoded signal and converting it signal into a synchronized set of binary characters. A charge pump phase-locked loop receives a transmitted reference clock and derives a multi-phase clock from the reference clock. The multi-phase clock is used to control a plurality of multi-bit block assembly circuits. Each assembly circuit receives one channel of the digital signal and produces a multi-bit block or…
System and method for sending multiple data signals over a serial link
Granted: November 10, 1998
Patent Number:
5835498
A system and method for sending multiple data signals over a serial link comprises an embedding unit and a removing unit coupled by a serial line. The embedding unit preferably receives a plurality of data streams, encodes the data streams and then merges the encoded data into a serial stream that is output across a serial line to the removing unit. The removing unit receives a serial stream of data, decodes the serial stream, and then separates the decoded serial stream into separate…
DC-balanced and transition-controlled encoding method and apparatus
Granted: October 20, 1998
Patent Number:
5825824
A method and apparatus for producing a transition-controlled, DC-balanced sequence of characters from an input sequence of data bytes. The bits in each of the data bytes are selectively complemented in accordance with the number of logical `1` signals in each data byte in order to produce selectively complemented data blocks. A cumulative disparity is then determined between the logical values of different type included within ones of the selectively complemented data blocks previously…
High-speed and high-precision phase locked loop having phase detector with dynamic logic structure
Granted: September 29, 1998
Patent Number:
5815041
A phase lock loop includes a charge pump, a voltage controlled oscillator (VCO), and a phase frequency detector. The phase frequency detector has a dynamic logic structure. The phase frequency detector generates up and down signals for directing the charge pump to provide a voltage signal to the VCO to vary the frequency of the VCO clock. The difference between the up and down signals is indicative of the phase difference between the reference clock signal and the VCO clock. The phase…
