Patent ID: 8681028
Filing Date: 2014-03-25
Classification: H03M

Abstract:
1. An analog to digital converter that converts an input voltage to an AD conversion data, the analog to digital converter starting conversion of the input voltage when triggered by a start signal, the analog to digital converter comprising: a first pulse delay circuit having a plurality of delay units mutually connected to form a multi-stage delay unit, each delay unit included in the multi-stage delay unit having a pulse signal delayed by a delay time corresponding to an input voltage; a first encoding circuit that detects the number of delay units in the first pulse delay circuit through which the pulse signal passes during a predetermined measurement period, the first encoding circuit outputting the AD conversion data based on the number of delay units detected thereby; a voltage determining circuit that determines whether or not the input voltage is a specified voltage within an allowable input voltage range; and a timing generation circuit, in response to receiving the start signal, generates an end signal when the voltage determining circuit detects the input voltage is a specified voltage within an allowable input voltage range, the timing generation circuit determining the predetermined measurement period to be a time required for the pulse signal to pass through a predetermined number of the delay units which is specified in advance.