Cirrus Logic Inc.

Nadi Rafik Itani

Douglas R Holberg

David R Welland

Sandra Marie Johnson

Caiyi Wang

Argos R Cue

Jason Powell Rhode

Brannon Craig Harris

Alan Wayne Hansford

Syed Khalid Azim

Ash Prabala

Shih-chung Chao

A processing system for a charge coupled device (CCD) or CMOS imaging system includes a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA) having amplifiers of selectable current level to enable reduced data resolution in a preview display, a low power mode analog-to-digital converter (ADC) having a selectable narrow bit-width output and coupled to said VGA circuit, and a gain circuit coupled to said ADC. The single chip low-power analog front end produces digitized CCD data in either 13-bit, 12-bit or 10-bit formats at a first current level and 9-bit, 8-bit, or 6-bit formats at a second current level. The VGA amplifier includes symmetrical subcircuits which are independently actuable to enable full or reduced data resolution levels respectively for still image capture operation and video previewing on a separate preview screen.

Preview mode low resolution output system and method

A selectable threshold multimode gain control apparatus and method for a charge coupled device (CCD) or CMOS imaging system includes an automatic gain control (AGC) circuit which continuously controls gain in said CCD system to produce a mutually continuous combined target gain level. A processing system for an imager device includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA), an analog-to-digital converter (ADC) coupled to said CDS circuit, a digital gain circuit (DGC) coupled to said ADC, and an automatic gain control (AGC) circuit coupled to said DGC for controlling the CDS circuit and the DGC, as well as shutter timing for shutter gain.

Selectable threshold multimode gain control apparatus and method for setting mutually continuous analog, digital, and shutter gain levels

An image processor system for a charge coupled device (CCD) or CMOS imaging system includes a histogram-based automatic gain control (AGC) circuit which first controls gain by adjusting said CCD system and then for yet a higher gain level makes gain adjustments in said CDSVGA circuit and a digital gain circuit to produce a combined target gain level. A processing system for an imager device includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA), an analog-to-digital converter (ADC) coupled to said CDS circuit, a digital gain circuit (DGC) coupled to said ADC, and an automatic gain control (AGC) circuit coupled to said DGC for controlling the CDS circuit and the DGC, as well as shutter timing for shutter gain.

Histogram-based automatic gain control method and system for video applications

A gain characteristic correctable dynamic range enhancement system (DRES) receives input signals from an imager device connected to a correlated double sampling (CDS) circuit for receiving the video signal from the CCD imaging device. The dynamic range enhancement system includes a variable gain amplifier (VGA), and a limited bit-width analog-to-digital converter (ADC) which digitizes the analog signal received from the VGA. The output of the ADC is provided to an initial bit range position of a wider bit-width shifter connected to the output of the ADC. The DRES system correctably extends the dynamic range of the imager device, subject to offsets providing linearity corrections at predetermined trip points, subject to determined offset values, to ensure that there are no discontinuities in the system transfer function.

Successive approximation calibration apparatus, system, and method for dynamic range extender

An image processor system for a charge coupled device (CCD) or CMOS imaging system includes a correlated double sample and variable gain (CDSVGA) circuit for receiving data from a CCD system and an automatic gain control (AGC) circuit which first controls gain by adjusting said CCD system and then for yet a higher gain level makes gain adjustments in said CDSVGA circuit AND a digital gain circuit to produce a combined target gain level. A processing system for an imager device includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA), an analog-to-digital converter (ADC) coupled to said CDS circuit, a digital gain circuit (DGC) coupled to said ADC, and an automatic gain control (AGC) circuit coupled to said DGC for controlling the CDS circuit and the DGC. The processing circuitry includes an analog front end and a digital signal processing system for capturing full motion video and outputting a CCIR 601 4:2:2 YCrCb video data output for presentation on a user selected display.

Correlated double sampling variable gain amplifier circuit for use in a digital camera

A processing system for a charge coupled device (CCD) or CMOS imaging system includes a multi-mode, multiple current level, correlated double sample and variable gain (CDS/VGA) circuit for receiving data from a CCD system, subject to horizontal and vertical timing signals for the system which are locally generated by the processing system itself. The processing system particularly includes programmable timing circuitry for controlling the detection of pixel intensity values from elements of a two-dimensional pixel array, with a programmable low-frequency master vertical timing circuit driving a high-frequency horizontal timing circuit, wherein the vertical and horizontal timing signals are independently locally provided to the array from the analog processor actually sampling the array. The architecture of the processing system further includes a correlated double sampler, a black level clamp, and an A/D conversion module. The processing system includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA) having amplifiers of selectable current level to enable reduced data resolution, an analog-to-digital converter (ADC) having a selectable bit-width output and coupled to said VGA circuit, and a gain circuit coupled to said ADC. The single chip analog front end produces digitized CCD data in a bit formats corresponding to selected current level and data resolution. The VGA amplifier includes circuitry to enable selected data resolution levels respectively for still image capture and separate video display on another viewing screen.

CCD imager analog processor systems and methods

A processing system for a charge coupled device (CCD) or CMOS imaging system includes a multi-mode, multiple current level, correlated double sample and variable gain (CDS/VGA) circuit for receiving data from a CCD system, subject to horizontal and vertical timing signals for the system which are locally generated by the processing system itself. The processing system particularly includes programmable timing circuitry for controlling the detection of pixel intensity values from elements of a two-dimensional pixel array, with a programable low-frequency master vertical timing circuit driving a high-frequency horizontal timing circuit, wherein the vertical and horizontal timing signals are independently locally provided to the array from the analog processor actually sampling the array. The architecture of the processing system further includes a correlated double sampler, a black level clamp, and an A/D conversion module. The processing system includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA) having amplifiers of selectable current level to enable reduced data resolution, an analog-to-digital converter (ADC) having a selectable bit-width output and coupled to said VGA circuit, and a gain circuit coupled to said ADC. The single chip analog front end produces digitized CCD data in a bit formats corresponding to selected current level and data resolution. The VGA amplifier includes circuitry to enable selected data resolution levels respectively for still image capture and separate video display on another viewing screen.

Disclosed is a data converter and a method for converting a digital audio stream representing an analog signal that has been sampled at a certain rate. The circuit includes a divider that receives a clock signal associated with the digital audio stream and divides the clock signal by a selectable division factor. The division factor is set according to divider control signals. At the output of the divider is provided an internal clock signal. A frequency detection circuit receives the signal from the output of the divider, and the frequency detection circuit detects the original sampling rate of the audio signal based upon intrinsic characteristics (e.g., MCLK to LRCK ratio) of the digital audio stream. The frequency detection circuit, which may also be used with a separate rate detection circuit to accomplish its function, then generates the divider control signals to the divider to set the division factor in the divider such that the internal clock signal has a known relationship to the original sampling rate based on the sampling mode. A digital processing circuit then receives the internal clock signal from the divider, derives incoming data from the digital audio stream, and generates an output signal.

Frequency detect circuit for determining sample speed mode of decoded audio input data streams

A high voltage input pad and method for accepting electrostatic discharge (ESD) surges without damage to an input semiconductor amplifier. The protection system includes a metal gate, transistor, and n-well resistors which provide ESD protection. Protection is further provided against large voltages coupled to an amplifier by connecting an input bipolar junction transistor to the negative input connection of the amplifier. Negative surges are directed to ground with an anode grounded diode connected at its cathode to the negative input connection of the amplifier.

High voltage input pad system

A dynamic range enhancement system (DRES) receives input signals from an imager device connected to a correlated double sampling (CDS) circuit for receiving the video signal from the CCD imaging device. The dynamic range enhancement system includes a variable gain amplifier (VGA), and a limited bit-width analog-to-digital converter (ADC) which digitizes the analog signal received from the VGA. The output of the ADC is provided to an initial bit range position of a wider bit-width shifter connected to the output of the ADC. The DRES system includes a 2-bit ADC for extending the dynamic range of the imager device, which enhances the dynamic range of a 10 bit ADC to 13 bits.

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Austin, TX, United States of America

Nadi Rafik Itani