DA CONVERTER AND SOLID-STATE IMAGING DEVICE
First Claim
1. A DA converter comprising:
- a reference current generating circuit that generates a reference current;
a plurality of current sources that supply currents according to the reference current;
a voltage output circuit that outputs a voltage according to a current to be supplied thereto;
a plurality of switch circuits provided for the current sources respectively to each switch a connection of each of the current sources to the voltage output circuit or a predetermined load;
a control section that controls the plurality of switch circuits based on an input digital signal to select that of the plurality of current sources which is to be connected to the voltage output circuit, and outputs a voltage according to the digital signal from the voltage output circuit; and
a switch that stops an operation of at least one of the plurality of current sources based on a control signal from the control section, without stopping an operation of the reference current generating circuit.
1 Assignment
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Accused Products
Abstract
A DA converter includes: a reference current generating circuit that generates a reference current; current sources that supply currents according to the reference current; a voltage output circuit that outputs a voltage according to a current to be supplied thereto; switch circuits provided for the current sources respectively to each switch a connection of each of the current sources to the voltage output circuit or a predetermined load; a control section that controls the switch circuits based on an input digital signal to select that of the current sources which is to be connected to the voltage output circuit, and outputs a voltage according to the digital signal from the voltage output circuit; and a switch that stops an operation of at least one of the current sources based on a control signal from the control section, without stopping an operation of the reference current generating circuit.
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Citations
12 Claims
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1. A DA converter comprising:
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a reference current generating circuit that generates a reference current; a plurality of current sources that supply currents according to the reference current; a voltage output circuit that outputs a voltage according to a current to be supplied thereto; a plurality of switch circuits provided for the current sources respectively to each switch a connection of each of the current sources to the voltage output circuit or a predetermined load; a control section that controls the plurality of switch circuits based on an input digital signal to select that of the plurality of current sources which is to be connected to the voltage output circuit, and outputs a voltage according to the digital signal from the voltage output circuit; and a switch that stops an operation of at least one of the plurality of current sources based on a control signal from the control section, without stopping an operation of the reference current generating circuit. - View Dependent Claims (2, 3, 4, 5)
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6. A solid-state imaging device comprising:
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a plurality of pixels laid out in a matrix form for converting an amount of input light to an electric signal; a row scan circuit that selectively controls the plurality of pixels row by row; a DA converter that generates a reference voltage according to an input digital signal; and a plurality of AD converters that compare analog signals acquired from the pixels with the reference voltage generated by the DA converter to convert the analog signals to digital signals, the DA converter including a reference current generating circuit that generates a reference current, a plurality of current sources that supply currents according to the reference current, a voltage output circuit that outputs a voltage according to a current to be supplied thereto, a plurality of switch circuits provided for the current sources respectively to each switch a connection of each of the current sources to the voltage output circuit or a predetermined load, a control section that controls the plurality of switch circuits based on the input digital signal to select that of the plurality of current sources which is to be connected to the voltage output circuit, and outputs a voltage according to the digital signal from the voltage output circuit, and a switch that stops an operation of at least one of the plurality of current sources based on a control signal from the control section, without stopping an operation of the reference current generating circuit. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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Specification