Sequential comparing type a/d converting circuit

Abstract

Abstract PURPOSE:To improve the charging rate of an analog input voltage to the capacity of a sampling without deteriorating converting accuracy by respectively individually providing chopper type comparators for comparing the most significant bit and for comparing a second and subsequent bits and executing the comparing operation of a former and the sampling operation of a latter in parallel. CONSTITUTION:During the comparison and the operation of the most significant bit, an analog input voltage Vin for comparing the second and subsequent bits is previously sampled and started in a sampling capacity 8 holed with a second chopper type comparator 2. At the time t3 in the vicinity of completing the comparing operation of the most significant bit, when a sampling period for comparing the second and subsequent bits is completed, the comparison operation of the second bit at a comparatively early time t4 succeeding thereto can be started. Thereby, the charging rate of the analog input voltage Vin to the sampling capacity 8 can be improved without lowering the converting accuracy or the converting speed.

Inventors

• 👤 Tatsuro Totani
• 👤 Nobutaka Nagasaki
• 👤 Hiroyuki Matsuura

Bibliographic Details