Patent ID: 7511547

Claim:
A delay circuit for delaying an input signal according to a desired delay time setting and outputting the same, comprising: a delay element for delaying the input signal for a time period based on a given supply current and outputting the same; a current supply section for generating the supply current; a voltage generating section for generating a base voltage according to the delay time setting, the voltage generating section including: a base current source for generating a plurality of base currents with different magnitude dependent on the resolution of the delay time setting; and a current-voltage converting section for amplifying each of the base currents according to the delay time setting and generating the base voltage based on the sum of the amplified base currents, the current-voltage converting section including: a plurality of delay amount converting current generating circuits for amplifying the base current with different amplifications from each other; a selecting section for selecting one or more of the delay amount converting current generating circuits based on the delay time setting; and a converter for generating the base voltage based on the sum of the current amplified by the delay amount converting current generating circuits selected by the selecting section, each of the delay amount converting current generating circuits including: a delay amount converting current path electrically connected to the converter; and a dummy current circuit provided in parallel with the delay amount converting current path and not electrically connected to the converter, wherein the selecting section applies the current amplified by the selected delay amount converting current generating circuit to the delay amount converting current path to cause the converter to provide the same, and applies the current amplified by the delay amount converting current generating circuits which are not selected to the dummy current path; and a control section for converting the base voltage dependent on a characteristic of the current supply section and providing the same to the current supply section in order to cause the current supply section to generate the supply current.