Patent ID: 7635996

Claim:
A differential blocking sampler comprising two main semi-samplers each having a respective differential input and a respective differential output, each semi-sampler comprising a storage capacitor and a voltage tracking transistor having an emitter driven by a constant current source during sampling periods and a base connected to the respective differential input, said voltage tracking transistor operating as a voltage tracker to continuously track the voltage on the respective differential input during sampling periods and being blocked during blocking periods, the emitter of said voltage tracking transistor being connected to the respective storage capacitor so that the voltage on the capacitor follows the voltage on said emitter during said sampling periods and is held during said blocking periods, wherein with each main semi-sampler is associated a respective auxiliary blocking semi-sampler comprising an auxiliary tracking transistor having a collector powered by a terminal of the storage capacitor of the other main semi-sampler and an emitter driven by a constant current source during said sampling periods, an auxiliary storage capacitor linked to the emitter of the auxiliary tracking transistor, an auxiliary current switch for authorizing, during said sampling periods, or blocking, during said blocking periods, the passage of current in the auxiliary tracking transistor, and a means for applying to a base of the auxiliary tracking transistor a voltage which tracks the voltage on the respective differential input of said each main semi-sampler.