FINE CONTROL TYPE DIGITAL-ANALOG CONVERTER AND FINE CONTROL METHOD USING THE SAME, ESPECIALLY DETERMINING UPPER BITS OF SAR ACCORDING TO ONE-HOT-ENCODING METHOD AND DETERMINING LOWER BITS OF SAR ACCORDING TO LEVEL SHIFT METHOD

摘要

PURPOSE: A fine control type digital-analog converter and a fine control method using the same are provided to minimize an area of an ADC by determining upper bits of an SAR(Successive Approximation Register) according to one-hot-encoding method and determining lower bits of the SAR according to a level shift method. CONSTITUTION: A selective signal generator(100) is used for providing SEL signals of 2¬4 number in order to perform a decoding process for upper 4-bits signals of 6-bits signals of SAR by using one-hot-encoding method. A reference voltage generator(110) includes a plurality of resistors connected between a supply power source and a ground power source in order to generate a reference voltage. A first inverter(120) and a second inverter(130) are connected to an output terminal of the selective signal generator. Transmission gates(140) of 2¬4 number are used for receiving node voltages among each resistor and are turned on according to logic signals of the first and the second inverters.