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US 5,517,152 AGranted
Current source circuit and operating method thereof
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTakahiro Miki, Yasuyuki Nakamura, Shiro Hosotani
Life of this patent
Estimating the term…
Abstract
A current source circuit according to the present invention is provided with an output terminal 100, a bias voltage source 21, N channel MOS transistors 2 and 1 and P channel MOS transistor 3. The source of transistor 2, the drain of transistor 1 and the drain of transistor 3 are connected to a common node, the drain of transistor 2 is connected to output terminal 100 and the gate of transistor 2 is connected to bias voltage source 21. Conductions of transistors 1 and 3 are dynamically controlled in response to an external signal. As a result, it is possible to implement a current source circuit having a small number of devices and enabling an operation at a high speed.
Claims29
A current source circuit, comprising:
- first and second transistors establishing a first series current flow path between a source of first constant potential and an output current terminal;
- a third transistor of conductivity type opposite that of said second transistor for establishing a second series current flow path between a source of second constant potential and one conduction terminal of said first transistor;
- a control electrode of said first transistor receiving a signal of a third constant potential so that said first transistor operates in a constant current region;
- and
- control electrodes of said second and third transistors connected to receive a control voltage for controlling a prescribed operating state of said current source.
2 more elements
A current source circuit, comprising:
- first and second transistors establishing a first series current flow path between a source of first constant potential and an output current terminal;
- a third transistor of conductivity type opposite that of said second transistor for establishing a second series current flow path between a source of second constant potential and one conduction terminal of said first transistor;
- a control electrode of said first transistor receiving a signal of third constant potential;
- and
- control electrodes of said second and third transistors connected to receive a control voltage for controlling a predetermined operating state of said current source, and further
- comprising a fourth transistor in said first series current flow path, said fourth transistor having a control electrode receiving a fourth constant potential.
3 more elements
A current source circuit, comprising:
- a first output terminal supplying an output current;
- a first semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- a second semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- a third semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said second semiconductor device;
- and a first bias voltage source for biasing said first semiconductor device in a constant current region, wherein
- said first conduction terminal of said first semiconductor device, said second conduction terminal of said second semiconductor device and said second conduction terminal of said third semiconductor device are connected to a common node;
- said second conduction terminal of said first semiconductor device is connected to said first output terminal;
- and
- said control terminal of said first semiconductor device is connected to said first bias voltage source;
- and
- said current source circuit further comprising:
- means for controlling dynamically conduction of said second and third semiconductor devices in response to an external signal.
9 more elements
A current source circuit comprising:
- a first output terminal supplying a first output current;
- a first bias voltage source;
- a first semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- a second semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- and
- a third semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said second semiconductor device;
- wherein
- said first conduction terminal of said first semiconductor device, said second conduction terminal of said second semiconductor device and said second conduction terminal of said third semiconductor device are connected to a common node;
- said second conduction terminal of said first semiconductor device is connected to said first output terminal;
- and
- said control terminal of said first semiconductor device is connected to said first bias voltage source;
- said current source circuit further comprising:
- means for controlling dynamically the conduction of said second and third semiconductor devices in response to an external signal;
- a fourth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said first semiconductor device;
- and
- a second bias voltage source;
- wherein
- said first conduction terminal of said fourth semiconductor device is connected to said first conduction terminal of said first semiconductor device;
- and
- said control terminal of said fourth semiconductor device is connected to said second bias voltage source,
- further comprising:
- a second output terminal separated from said first output terminal for supplying a second output current;
- wherein
- said second conduction terminal of said fourth semiconductor device is connected to said second output terminal.
21 more elements
In a current source circuit comprising:
- a first output terminal supplying an output current;
- a first semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- a second semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- and
- a third semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said second semiconductor device;
- and,
- a first bias voltage source for biasing said first semiconductor device in a constant current region;
- wherein
- said first conduction terminal of said first semiconductor device, said second conduction terminal of said second semiconductor device and said second conduction terminal of said third semiconductor device are connected to a common node;
- said second conduction terminal of said first semiconductor device is connected to said first output terminal;
- said control terminal of said first semiconductor device is connected to said first bias voltage source
- said second semiconductor device is rendered operative in a non-constant current region while said third semiconductor device is rendered non-conductive in response to an external signal;
- and
- said second semiconductor device non-conductive while said third semiconductor device is rendered conductive.
11 more elements
A current source circuit, comprising:
- a first output terminal and a second output terminal each supplying an output current;
- a first bias voltage source;
- a first semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- a second semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- and
- a third semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said second semiconductor device;
- wherein
- said first conduction terminal of said first semiconductor device, said second conduction terminal of said second semiconductor device and said second conductive terminal of said third semiconductor device are commonly connected to a first node;
- said second conduction terminal of said first semiconductor device is connected to said first output terminal;
- said current source circuit further comprising:
- a fourth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of the same conductivity type as that of said first semiconductor device;
- a fifth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of the same conductivity type as that of said second semiconductor device;
- and
- a sixth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said fifth semiconductor device;
- wherein
- said first conduction terminal of said fourth semiconductor device, said second conduction terminal of said fifth semiconductor device and said second conduction terminal of said sixth semiconductor device are commonly connected to a second node;
- said second conduction terminal of said fourth semiconductor device is connected to said second output terminal;
- and
- said control terminals of said first and fourth semiconductor devices are commonly connected to said first bias voltage source;
- said current source circuit further comprising:
- means for controlling dynamically conductions of said second, third, fifth and sixth semiconductor devices according to external signals.
18 more elements
In a current source circuit comprising:
- first output terminal and a second output terminal each supplying an output current;
- a first bias voltage source;
- a first semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- a second semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal;
- and
- a third semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said second semiconductor device;
- wherein
- said first conduction terminal of said first semiconductor device, said second conduction terminal of said second semiconductor device and said second conduction terminal of said third semiconductor device are commonly connected to a first node;
- and
- said second conduction terminal of said first semiconductor device is connected to said first output terminal;
- said current source circuit further comprising:
- a fourth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of the same conductivity type as that of said first semiconductor device;
- a fifth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of the same conductivity type as that of said second semiconductor device;
- and
- a sixth semiconductor device having a first conduction terminal, a second conduction terminal and a control terminal and being of a conductivity type opposite to that of said fifth semiconductor device;
- wherein
- said first conduction terminal of said fourth semiconductor device, said second conduction terminal of said fifth semiconductor device and said second conduction terminal of said sixth semiconductor device are commonly connected to a second node;
- said second conduction terminal of said fourth semiconductor device is connected to said second output terminal;
- and
- said control terminals of said first and fourth semiconductor devices are commonly connected to said first bias voltage source;
- said second semiconductor device is rendered operative in a non-constant current region, said sixth semiconductor device is rendered conductive while said third and fifth semiconductor devices are rendered non-conductive in response to external signals;
- and
- said fifth semiconductor device is rendered operative in a non-constant current region, said third semiconductor device is rendered conductive while said second and sixth semiconductor devices are rendered non-conductive.
20 more elements
A current source circuit, comprising:
- a first transistor of a first conductivity type connected between a connecting node and a first potential node, the control electrode of said first transistor receiving a first driving signal;
- a second transistor of a second conductivity type connected between said connecting node and a second potential node, the control electrode of said second transistor receiving a second driving signal;
- and
- a third transistor of a first conductivity type connected between said connecting node and an output node, the control electrode of said third transistor receiving a signal of a bias potential so that said third transistor operates in a constant current region.
1 more element
A current source circuit, comprising:
- a first transistor of a first conductivity type connected between a connecting node and a first potential node, the control electrode of said first transistor receiving a first driving signal;
- a second transistor of a second conductivity type connected between said connecting node and a second potential node, the control electrode of said second transistor receiving a second driving signal;
- and
- a transistor group having a plurality of transistors serially connected between said connecting node and an output node, the control electrode of each transistor applied a bias potential, respectively.
1 more element
A current source circuit, comprising:
- a first transistor of a first conductivity type connected between a first connecting node and a first potential node, the control electrode of said first transistor receiving a first driving signal;
- a second transistor of a second conductivity type connected between said first connecting node and a second potential node, the control electrode of said second transistor connected to a second connecting node;
- a third transistor of a first conductivity type connected between said first connecting node and a first output node, the control electrode of said third transistor receiving a bias potential;
- a fourth transistor of a first conductivity type connected between said second connecting node and said first potential node, the control electrode of said fourth transistor receiving a second driving signal;
- a fifth transistor of a second conductivity type connected between said second connecting node and said second potential node, the control electrode of said fifth transistor connected to said first connecting node;
- and
- a sixth transistor of a first conductivity type connected between said second connecting node and a second output node, the control electrode of said sixth transistor receiving a bias potential.
4 more elements
A current source circuit, comprising:
- a first transistor of a first conductivity type connected between a first connecting node and a first potential node, the control electrode of said first transistor connected to a second connecting node;
- a second transistor of a second conductivity type connected between said first connecting node and a second potential node, the control electrode of said second transistor receiving a first driving signal;
- a third transistor of a first conductivity type connected between a first connecting node and said first output node, the control electrode of said third transistor receiving a bias potential,
- a fourth transistor of a first conductivity type connected between said second connecting node and said first potential node, the control electrode of said fourth transistor connected to said first connecting node;
- a fifth transistor of a second conductivity type connected between said second connecting node and said second potential node, the control electrode of said fifth transistor receiving a second driving signal;
- and
- a sixth transistor of a first conductivity type connected between said second connecting node and a second output node, the control electrode of said sixth transistor receiving a bias potential.
4 more elements
A current source circuit comprising:
- a first transistor of a first conductivity type connected between a first connecting node and a first potential node, the control electrode of said first transistor connected to a second connecting node;
- a second transistor of a second conductivity type connected between said first connecting node and a second potential node, the control electrode of said second transistor receiving a first driving signal;
- a third transistor of a first conductivity type connected between a first connecting node and said first output node, the control electrode of said third transistor applied a first bias potential,
- a fourth transistor of a first conductivity type connected between said second connecting node and said first potential node, the control electrode of said fourth transistor connected to said first connecting node;
- a fifth transistor of a second conductivity type connected between said second connecting node and said second potential node, the control electrode of said fifth transistor receiving a second driving signal;
- and
- a sixth transistor of a first conductivity type connected between said second connecting node and said second output node, the control electrode of said sixth transistor applied a second bias potential,
- wherein said first and second bias potentials are the same potential.
5 more elements
A current source circuit, comprising:
- a first transistor of a first conductivity type connected between a connecting node and a first potential node, the control electrode of said first transistor receiving a first driving signal;
- a second transistor of a second conductivity type connected between said connecting node and a second potential node, the control electrode of said second transistor receiving a second driving signal;
- a third transistor of a first conductivity type connected between said connecting node and a first output node, the control electrode of said third transistor receiving a signal of a first bias potential so that said third transistor operates in a constant current region;
- and
- a fourth transistor of a second conductivity type connected between said connecting node and a second output node, the control electrode of said fourth transistor receiving a signal of a second bias potential so that said fourth transistor operates in a constant current region.
2 more elements
Dependencies are inferred from the claim text.