Apparatus for high speed analog-to-digital conversion by localizing an input voltage to a voltage range

Abstract

An analog-to-digital converter ( ) for sampling high speed video signals includes a first input ( ) for receiving an electronic signal, a sampling clock input ( ) for receiving a sampling clock signal, and first and second sampling circuits. The first sampling circuit is arranged in a differential circuit arrangement, and is electrically connected to the first input ( ) and to the sampling clock input ( ) and is responsive to the sampling clock signal, for sampling the electronic signal to provide a pair of boundary reference voltage signals ( ) that bound the voltage of the sampled electronic signal, and further to convert the sampled electronic signal to provide the most significant bits ( ) of a digital representation of the electronic signal at times indicated by the sampling clock signal. The second sampling circuit is arranged in a differential circuit arrangement, and includes an interpolation circuit ( ) electrically connected to the first sampling circuit, for sampling an interpolated signal corresponding to the pair of boundary reference voltage signals ( ), and further to convert the sampled interpolated signal to provide the least significant bits ( ) of the digital representation of the sampled electronic signal at times indicated by the sampling clock signal. A video display monitor system ( ) includes analog-to-digital converters ( ).