Abstract: An analog-to-digital converting system with automatic gain control. The analog-to-digital converting system includes a programmable gain amplifier (PGA) for receiving and amplifying an input signal by a gain factor to generate an amplified input signal; an ADC, coupled to the PGA, for converting the amplified input signal into a digital signal according to an actual reference voltage signal; and an automatic gain controller, coupled to the PGA and the ADC, for jointly controlling the gain factor set to the PGA and the actual reference voltage signal set to the ADC according to a hysteretic behavior.

Abstract: An analog-to-digital converting system for converting a composite video signal into a digital signal according to a synchronized clock. The analog-to-digital converting system includes an analog-to-digital converter (ADC), a color burst phase estimator and a phase-locked loop (PLL). The ADC converts the composite video signal to the digital signal according to the synchronized clock, wherein the synchronized clock is synchronized to a frequency of a color burst of a chrominance signal of the composite video signal. The color burst phase estimator, coupled to the ADC, estimates the phase of the color burst carried on the composite video signal. The PLL, coupled to the color burst phase estimator, generates the synchronized clock according to the phase of the color burst estimated by the color burst phase estimator.

Abstract: A level clamping control circuit and associated level clamping control method are provided. The level clamping control circuit includes a reference level estimator, a subtractor, a clamping computation circuit, a dithering circuit, and a digital-to-analog converter (DAC). The reference level estimator estimates a reference level of the input signal. The subtractor computes a difference between the reference level and a desired reference level to output a difference signal. The clamping computation circuit generates a first control value according to the difference signal. The dithering circuit dithers the first control value to alternately output a plurality of second control values. Finally, the DAC respectively utilizes the second control values to charge or discharge a capacitor to adjust the reference level of the input signal.

Abstract: An analog-to-digital converting system for converting a composite video signal into a digital signal according to a synchronized clock. The analog-to-digital converting system includes an analog-to-digital converter (ADC), a color burst phase estimator and a phase-locked loop (PLL). The ADC converts the composite video signal to the digital signal according to the synchronized clock, wherein the synchronized clock is synchronized to a frequency of a color burst of a chrominance signal of the composite video signal. The color burst phase estimator, coupled to the ADC, estimates the phase of the color burst carried on the composite video signal. The PLL, coupled to the color burst phase estimator, generates the synchronized clock according to the phase of the color burst estimated by the color burst phase estimator.

Abstract: A level clamping control circuit and associated level clamping control method are provided. The level clamping control circuit includes a reference level estimator, a subtractor, a clamping computation circuit, a dithering circuit, and a digital-to-analog converter (DAC). The reference level estimator estimates a reference level of the input signal. The subtractor computes a difference between the reference level and a desired reference level to output a difference signal. The clamping computation circuit generates a first control value according to the difference signal. The dithering circuit dithers the first control value to alternately output a plurality of second control values. Finally, the DAC respectively utilizes the second control values to charge or discharge a capacitor to adjust the reference level of the input signal.

Abstract: An analog-to-digital converting system with automatic gain control. The analog-to-digital converting system includes a programmable gain amplifier (PGA) for receiving and amplifying an input signal by a gain factor to generate an amplified input signal; an ADC, coupled to the PGA, for converting the amplified input signal into a digital signal according to an actual reference voltage signal; and an automatic gain controller, coupled to the PGA and the ADC, for jointly controlling the gain factor set to the PGA and the actual reference voltage signal set to the ADC according to a hysteretic behavior.