摘要:
DAC includes a decoder that receives N number of reference voltages and an n-bit digital signal (n 4) to select first to third voltages, and an operational amplifier to output (first voltage+second voltage+2 third voltage)/4 voltage. The operational amplifier is able to output, for respective 2^n combinations of the n-bit digital signal, voltage levels from an Ath level, as a base level, to an (A−1+2^n)th level. The N number of reference voltages include Ath level, (A+4)th level, (A−4+2^n) and (A+2^n), and an at most {−4+2^(n−2)} reference voltages obtained by decimating a pre-set at least one reference voltage from {−3+2^(n−2)} reference voltages that are other than the four number of reference voltages from the {1+2^(n−2)} reference voltages corresponding to the voltage levels spaced each other at an interval of 4 levels from the Ath level. N is not less than 4 and not more than 2^(n−2).
摘要:
Reference voltages of a reference voltage ensemble are classed into first to (z×S+1)th reference voltage groups, where S is a power of 2 inclusive of 1 and z is a power of 2 plus 1. A decoder includes first to (z×S+1)th sub-decoders provided in association with the first to (z×S+1)th reference voltage groups, and a (z×S+1) input and 2 output type sub-decoder. The first to (z×S+1)th sub-decoders select, from the reference voltage of the first to the (z×S+1)th reference voltage groups, those reference voltages allocated to columns in a two-dimensional array of the reference voltages associated with the values of a first bit group of an input digital signal. The (z×S+1) input and 2 output sub-decoder receives outputs of the first to (z×S+1)th sub-decoders to select the first and second voltages from the reference voltages selected by the first to (z×S+1)th sub-decoders in response to the value of a second bit group of the input digital signal. An interpolation circuit receives the first and second voltages, selected by the decoder, to output a voltage level obtained on interpolation with an interpolation ratio of 1:1 (FIG. 1).
摘要:
Disclosed is an output circuit including a differential amplifier stage, an output amplifier stage, an amplification acceleration circuit and a capacitance connection control circuit. The output amplifier stage includes push/pull type transistors connected an output terminal. The amplification acceleration circuit includes a first switch and a first transistor, connected between a first output of the differential amplifier stage and the output terminal, and a second transistor and a second switch connected between the output terminal and a second output of the differential amplifier stage. The capacitance connection control circuit includes first capacitive element having first end connected to the output terminal, a first switch connected between a second end of the first capacitive element and a first voltage supply terminal, and a second switch connected between the second end of the first capacitive element and one output of a first differential pair of the differential amplifier stage.
摘要:
An output circuit is capable of supporting a high-speed operation, suppressing power consumption, and controlling its area. The output circuit has a differential input stage, an output amplification stage, and an amplification boost circuit, in which the amplification boost circuit has a differential pair of a second conductivity type and load element pair, and includes a first current source circuit for controlling current supply to an input node of a second current mirror circuit of the differential input stage and boost the charging operation of the output amplification stage according to a voltage difference between input and output voltages, and a second current source circuit for controlling current supply to an output node of a first current mirror circuit of the differential input stage and boost the discharging operation of the output amplification stage.
摘要:
A level shift circuit includes a first circuit connected between a first power supply terminal (PST) and an output terminal (OT) of the level shift circuit to set OT to a first voltage (V1) when conducting, a second circuit connected between a second PST and OT to set OT to the second voltage (V2) when conducting, and a third circuit that receives an input signal and a feedback signal from OT so that, when OT=V2 and input=a third voltage (V3), the first circuit conducts, and when OT=V1, the first circuit is made nonconductive irrespective of the value of the input signal. The second circuit is made conductive and nonconductive, when the input=a fourth voltage (V4) and V3, respectively. A high/low relationship of V1, V2=that of V3, V4. The input between V3, V4 has a lower amplitude than the output signal between V1, V2.
摘要:
A level shift circuit includes first and second NMOS transistors that are coupled between a first supply terminal, and first and second output nodes, respectively, and have respective control terminals receiving input signals of a low amplitude, third and fourth PMOS transistors which are coupled between a second supply terminal, and the first and second output nodes outputting signals of high amplitude, respectively, a fifth PMOS transistor which is coupled between a gate of the third PMOS transistor and the second output node, and has a gate coupled to the first output node, a sixth PMOS transistor which is coupled between a gate of the fourth PMOS transistor and the first output node, and has a gate coupled to the second output node, and first and second load elements which are coupled between the second supply terminal and the gates of the third and fourth PMOS transistors, respectively.
摘要:
Disclosed is a decoder, receiving the first and the second reference voltage groups and selecting a reference voltage in accordance with a received digital signal, including a first sub-decoder receiving the first reference voltage group, a second sub-decoder receiving the second reference voltage group 20B, and a third sub-decoder receiving a reference voltage selected by the second sub-decoder and outputting the selected reference voltage to the first sub-decoder or an output terminal of the decoder. The first sub-decoder includes a transistor of a first conductivity type having a back gate supplied with a first power supply voltage, the second sub-decoder includes a transistor of the first conductivity type having a back gate supplied with a second power supply voltage, and the third sub-decoder includes a transistor of the first conductivity type having a back gate supplied with a first power supply voltage. The first power supply voltage is a first reference voltage, which is a most spaced from the second voltage section among the first reference voltage group, or a predetermined voltage even further spaced from the second voltage section than the first reference voltage. The second power supply voltage is a predetermined voltage within a range from a second reference voltage, which is a voltage closest to the first voltage section among the second reference voltage group, to a voltage within the first voltage section but not reaching the first reference voltage.
摘要:
Disclosed is a level shift circuit that includes a first level shifter which is connected between an output terminal and a first power supply terminal that supplies a first voltage and sets the output terminal to a level of the first voltage when an input signal received at an input terminal assumes a first value; a second level shifter which is connected between the output terminal and a second power supply terminal that supplies a second voltage and sets the output terminal to a level of the second voltage when the input signal assumes a complementary value of the first value; and a feedback control unit that performs control of deactivating the first level shifter during a predetermined time interval including a point of time when the input signal is supplied when it is detected that the output terminal immediately before the input signal is received at the input terminal assumes the first voltage level. When the input signal supplied in the predetermined time interval assumes a value that sets the output terminal to the second voltage level, the second level shifter sets the output terminal to the second voltage level with the first level shifter deactivated.
摘要:
A digital-to-analog converter circuit includes: a first subdecoder for receiving a first reference voltage group and selecting a reference voltage Vrk based upon an input digital signal; a second subdecoder for receiving a second reference voltage group and selecting a reference voltage Vr(k+1) based upon the input digital signal; a third subdecoder for receiving a third reference voltage group and selecting a reference voltage Vr(k+2) based upon the input digital signal; a fourth subdecoder for receiving the reference voltages that have been selected by respective ones of the first to third subdecoders, selecting two of these reference voltages (inclusive of selecting the same voltage redundantly) based upon an input digital signal, and outputting the selected two reference voltages; and an amplifier circuit for receiving the two reference voltages that have been selected by the fourth subdecoder and outputting a result of an operation applied to the two reference voltages.
摘要:
Disclosed is a differential amplifier which includes first and second input terminals, an output terminal, first and second differential pairs, and first and second current sources for supplying currents to the first and second differential pairs. The first differential pair has first and second inputs of an input pair connected to the first input terminal and the output terminal, respectively. The second differential pair has first and second inputs of an input pair connected to the second input terminal the output terminal, respectively. The differential amplifier further includes a load circuit connected to output pairs of the first and second differential pairs for outputting a signal obtained on combining outputs of the first and second differential pairs from at least one of a pair of connection nodes between the output pairs of the first and second differential pairs and the load circuit, an amplifier stage supplied with at least one signal at a connection node of the output pairs of the first and second differential pairs and the load circuit to output a voltage at the output terminal, and a current control circuit controlling the first and second current sources for controlling the ratio of currents supplied to the first and second differential pairs.