METHOD AND APPARATUS FOR CONVERSION OF TIME INTERVAL TO DIGITAL WORD USING SUCCESSIVE APPROXIMATION SCHEME

摘要

A method for conversion of a time interval to a digital word using a successive approximation scheme characterized in that the time interval (T) is mapped to a difference of a length of a reference time (RT) and a length of a signal time (ST). The reference time (RT) is generated from an instant (t₁) when the beginning of the time interval (T) is detected, and the signal time (ST) is generated from an instant (t₂) when the end of the time interval (T) is detected by the use the control module (CM). The generation of the reference time (RT) and the signal time (ST) is terminated at the same instant (t₃).;An apparatus for conversion of a time interval to a digital word using a successive approximation scheme comprises a control module (CM), two comparators (K_R, K_S), two current sources (I_R, I_S), two rails (R, S) and a set of capacitors (CS). The apparatus is characterized in that bottom plates of capacitors (C_n-1, C_n-2, ..., C₁, C₀) of the set of capacitors (CS) are connected to a ground of the circuit, and top plates of these capacitors are connected respectively to moving contacts of change-over switches (S_n-1, S_n-2, ..., S₁, S₀). First stationary contacts are connected to the signal rail (S), second stationary contacts are connected to the ground of the circuit, and third stationary contacts are connected to the reference rail (R).