Differential amplifier, digital-to-analog converter, and display device
First Claim
1. A differential amplifier comprising:
- first and second input terminals and an output terminal;
a differential pair having a pair of inputs thereof connected to said first terminal and said second input terminal, respectively, said differential pair for performing voltage-to-current conversion of voltages at said first and second input terminals to output differential currents to first and second nodes, respectively;
a first current source for supplying a current to said differential pair;
a first load circuit connected to said first node, said first load circuit for performing current-to-voltage conversion of a current at said first node to a voltage at a third node;
a second load circuit connected to said second node, said second load circuit for reversibly performing mutual conversion between a current at said second node and a voltage at a fourth node and for supplying a voltage signal to a fifth node;
a capacitance element connected between said third node and said fourth node; and
an amplifier circuit for charging or discharging said output terminal based on the voltage signal at said fifth node;
wherein responsive to a control signal, said differential amplifier is subjected to switching control between first and second states, wherein in said first state, a first signal is supplied to said first input terminal, a second signal is supplied to said second input terminal, and a potential difference between the voltages at said third and fourth nodes output by said first and second load circuits, respectively, are stored in said capacitance element; and
wherein in said second state, a third signal is supplied to said second input terminal, a signal at said output terminal is fed back to said first input terminal, and the potential difference stored in said capacitance element in said first state is held and a voltage signal is output to said fifth node based on the potential difference.
1 Assignment
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Accused Products
Abstract
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.
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Citations
20 Claims
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1. A differential amplifier comprising:
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first and second input terminals and an output terminal;
a differential pair having a pair of inputs thereof connected to said first terminal and said second input terminal, respectively, said differential pair for performing voltage-to-current conversion of voltages at said first and second input terminals to output differential currents to first and second nodes, respectively;
a first current source for supplying a current to said differential pair;
a first load circuit connected to said first node, said first load circuit for performing current-to-voltage conversion of a current at said first node to a voltage at a third node;
a second load circuit connected to said second node, said second load circuit for reversibly performing mutual conversion between a current at said second node and a voltage at a fourth node and for supplying a voltage signal to a fifth node;
a capacitance element connected between said third node and said fourth node; and
an amplifier circuit for charging or discharging said output terminal based on the voltage signal at said fifth node;
wherein responsive to a control signal, said differential amplifier is subjected to switching control between first and second states, wherein in said first state,a first signal is supplied to said first input terminal, a second signal is supplied to said second input terminal, and a potential difference between the voltages at said third and fourth nodes output by said first and second load circuits, respectively, are stored in said capacitance element; and
whereinin said second state, a third signal is supplied to said second input terminal, a signal at said output terminal is fed back to said first input terminal, and the potential difference stored in said capacitance element in said first state is held and a voltage signal is output to said fifth node based on the potential difference. - View Dependent Claims (3, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15)
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2. A differential amplifier comprising:
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first and second input terminals and an output terminal;
a differential pair having a pair of inputs thereof connected to said first terminal and said second input terminal, respectively, said differential pair for performing voltage-to-current conversion of voltages at said first and second input terminals to output differential currents to first and second nodes, respectively;
a first current source for supplying a current to said differential pair;
a first load circuit connected to said first node, said first load circuit for performing current-to-voltage conversion of a current at said first node to a voltage at a third node;
a second load circuit connected to said second node, said second load circuit for reversibly performing mutual conversion between a current at said second node and a voltage at a fourth node and for supplying a voltage signal to a fifth node;
a capacitance element connected between said third node and said fourth node; and
an amplifier circuit for charging or discharging said output terminal based on the voltage signal at said fifth node;
whereina data output period of said differential amplifier includes first and second periods and responsive to a control signal, switching control between said first period and said second period is performed, wherein in said first period, a first signal is supplied to said first input terminal of said differential pair through a fourth switch in an on state;
a second signal is supplied to said second input terminal of said differential pair through a second switch in the on state;
said second and fourth nodes are short-circuited by a first switch in the on state; and
a potential difference between said third and fourth nodes is stored in said capacitance element; and
whereinin said second state, said first, second, and fourth switches are all turned off, said output terminal is feedback connected to said first input terminal of said differential pair through a fifth switch in the on state, and a third signal is supplied to said second input terminal of said differential pair through a third switch in the on state. - View Dependent Claims (4, 7)
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16. A differential amplifier comprising:
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first through third input terminals and an output terminal;
a load circuit including;
a first transistor with a first end thereof connected to a first power supply;
a second transistor with a first end thereof connected to said first power supply; and
a capacitor connected between a control terminal of said first transistor and a control terminal of said second transistor;
a differential pair including third and fourth transistors with first ends thereof connected in common and with second ends thereof connected to second ends of said first and second transistors, respectively;
a control terminal of said first transistor being connected to the second terminal of said third transistor;
a current source connected between a second power supply and the commonly coupled first ends of said third and fourth transistors, said current source for supplying a current to said differential pair;
a first switch connected between said control terminal of said second transistor and the second end of said fourth transistor;
an amplifier with an input thereof connected to the second end of said second transistor and an output thereof connected to said output terminal;
a second switch connected between a control terminal of said fourth transistor and said first input terminal and a third switch connected between said control terminal of said fourth transistor and said third input terminal;
a fourth switch connected between a control terminal of said third transistor and said second input terminal; and
a fifth switch connected between said control terminal of said third transistor and said output terminal;
said control terminal of said first transistor being connected to the second end of said third transistor;
said first through fifth switches being subject to switching control between a first state and a second state, wherein in said first state, said first, second, and fourth switches are set in an ON state and said third and fifth switches are set in an OFF state; and
in said second state, said first, second, fourth switches being set in an OFF state and said third and fifth switches being set in an ON state. - View Dependent Claims (17, 18, 19, 20)
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Specification