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 digital-to-analog converter circuit having first to (2×h+1)th reference voltages (where h is a prescribed positive integer) grouped into the following groups: a first reference voltage group comprising h-number of (2×j−1)th (where j is a prescribed positive integer of 1 to h) reference voltages; a second reference voltage group comprising h-number of (2×j)th reference voltages; and a third reference voltage group comprising h-number of (2×j+1)th reference voltages. The digital-to-analog converter circuit includes: a first subdecoder for receiving the first reference voltage group and selecting a reference voltage Vrk based upon an input digital signal; a second subdecoder for receiving the second reference voltage group and selecting a reference voltage Vr(k+1) based upon the input digital signal; a third subdecoder for receiving the 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 Vr, Vr(k+1), and Vr(k+2) that have been selected by respective one 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 result of an operation applied to the two reference voltages.
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:
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:
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:
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.
摘要:
Disclosed is a differential amplifier of a multi-level output type comprising a load circuit including a diode-connected first transistor with a source thereof connected to a power supply and a second transistor with a source thereof connected to the power supply and connected to a gate of the first transistor through a capacitor, a differential pair including a third transistor and a fourth transistor with sources thereof connected in common and drains thereof connected to drains of the first and second transistors, respectively, a current source for supplying a current to the differential pair, a first switch connected between a gate of the second transistor and a drain of the fourth transistor, an amplifier with an input thereof connected to a drain of the second transistor and an output thereof connected to an output terminal, a second switch connected between a gate of the fourth transistor and a first input terminal, a third switch connected between the gate of the fourth transistor and a third input terminal, a fourth switch connected between a gate of the third transistor and a second input terminal, and a fifth switch connected between the gate of the third transistor and the output terminal. Switching control between a first state where the first, second and fourth switches are turned on and the third and fifth switches are turned off and a second state where the first and second fourth switches are turned off and the third and fifth switches are turned on is performed.
摘要:
A differential amplifier includes a first differential pair, a second differential pair, a load circuit, connected in common to the first and second differential pairs, and first and second current sources for supplying the current to the first and second differential pairs, and amplifies a signal responsive to a common output signal of the first and second differential pairs. One of differential inputs of the first differential pair is connected to a reference voltage. A data output period includes a first period and a second period. During the first period, voltages of first and second input terminals are input through first and fourth switches in the on-state to differential inputs of the second differential pair. The other of the differential inputs of the first differential pair is connected through a third switch in the on-state to an output terminal. An output voltage is stored in a capacitor C connected to the other differential input of the first differential pair. The first, third and fourth switches are turned off during the second period. One of the differential inputs of the second differential pair is connected through a second switch to the output terminal. The other differential input of the second differential pair is connected through a fifth switch to a third input terminal.