ESS Technology Incorporated is a private manufacturer of computer multimedia products, Audio DAC's and ADCs based in Fremont, California with R&D centers in Kelowna, BC Canada and Beijing, China. It was founded by Fred Chan and Forrest Mozer in 1984. Robert L. Blair is the CEO and President of the company.Historically, ESS Technology was most famous for their line of their Audiodrive chips for audio cards. Now they are known for their line of Sabre DAC and ADC products. Wikipedia.
ESS Technology | Date: 2015-07-02
A system and method is disclosed for placing some of the elements of a FIR filter into a high impedance state in certain situations. When it is detected that the signal to an impedance element is the same as the previous value, then the driver of that impedance element is turned off or goes into a high impedance state, so that no current flows through that impedance element, and it no longer contributes to the filter output. Alternatively, if the impedance elements are the same between two adjacent taps of the delay line, the driver of one of those impedance elements may be turned off or go into a high impedance state. The technique may be particularly useful in differential output filters. Turning off a driver effectively removes the attached impedance element from the filter and reduces current flow and power consumption, thus extending battery life in mobile devices.
ESS Technology | Date: 2015-10-22
An apparatus is disclosed for inputting digital data on the output channel(s) of an audio subsystem in an audio device, without interfering with normal operation of the audio subsystem. The described circuit includes a resistive element in parallel with the expected load device, such as a headphone or speaker. The resistive element receives a modulated digital signal from a data source or a switch, and the instantaneous current through the resistive element due to the modulated digital signal is reflected in a current feedback mechanism of the audio subsystem. Demodulation logic retrieves the digital signal from the current measured by the current feedback mechanism. A capacitor is provided to prevent the current in the resistive element from the digital signal from impacting the average DC current that the feedback mechanism uses to evaluate the load device.
ESS Technology | Date: 2014-08-06
An improved method for the placement and routing of compound elements, each comprising a series/parallel combination of nominally identical elements, is disclosed. The method treats each compound element as a separate cell (the sub-circuit construct commonly used in silicon chip design) so as to treat as a unit all the nominally identical elements that make up a compound value, and place them as a single group in the design of a chip. This results in the compound elements being placed as units and routed in such a way that all of the nominal elements are located together and any effects between compound values are thus relatively localized and optimally isolated.
ESS Technology | Date: 2013-10-16
A method and system is disclosed in which the phase detector in a phase-locked loop is able to run at the fastest speed appropriate for a reference signal. A frequency offset is added, to the output frequency of the phase-locked loop, to alter the frequency fed to the frequency divider which would receive the output frequency in a conventional PLL to an intermediate frequency. The frequency offset is selected so that the ratio of the intermediate frequency to the reference frequency is a simple fraction, and preferably an integer, i.e., the intermediate frequency is a multiple of the reference frequency. In cases where the relationship between the output frequency and the reference frequency is largely relatively prime, the phase detector is thus able to receive signals at the frequency of the reference signal and operate at the fastest speed appropriate for the reference signal.
ESS Technology | Date: 2014-12-12
An apparatus is disclosed for providing a common mode voltage to the inputs of a first differential amplifier which outputs the difference between two signals. A second differential amplifier receives the output of the first differential amplifier, and the output of the second differential amplifier is fed back to the inputs of the first differential amplifier as a common mode voltage. Since both inputs of the first differential amplifier receive the fed hack common mode voltage, the first differential amplifier still outputs only the difference in the two signals, but the presence of the common mode voltage allows the first differential amplifier to operate with lower noise if the voltage levels of the inputs to the first differential amplifier vary. The second differential amplifier may be of significantly lower quality and cost than the first differential amplifier, without affecting the performance of the first differential amplifier.