Current/voltage converter and D/A converter

A D/A converter comprising:

• a current generating circuit which is connected to a first node, and which generates the total current corresponding to a digital signal;
• a first transistor element connected between the first node and a power supply or the ground;
• a second transistor element which is connected between a second node and the power supply or the ground, of which the control terminal is connected to that of the first transistor element, and which is of the same conductive type as the first transistor element;
• a first control circuit which uses a bias voltage as one of the inputs thereto, and which controls the voltages of the control terminals of said first and second transistor elements so that the voltage of said first node becomes substantially equal to said bias voltage;
• a second control circuit which uses said bias voltage as one of the inputs thereto, and which controls the voltage of said second node so as to become substantially equal to that of said first node;
• and
• a resistance element one end of which is connected to said second node, and which converts the current flowing through said second transistor element into a voltage.

A D/A converter comprising:

• a current generating circuit which is connected to a first node, and which generates the total current corresponding to a digital signal;
• a first transistor element connected between the first node and a power supply or the ground;
• a second transistor element which is connected between a second node and the power supply or the ground, of which the control terminal is connected to that of the first transistor element, and which is of the same conductive type as the first transistor element;
• a first control circuit which uses a bias voltage as one of the inputs thereto, and which controls the voltages of the control terminals of said first and second transistor elements so that the voltage of said second node becomes substantially equal to that of said first node;
• a resistance element one end of which is connected to the power supply or the ground, and which converts the current flowing through said second transistor element into a voltage;
• a third transistor element connected between the second node and the other end of said resistance element;
• and
• a second control circuit which uses said bias voltage as one of the inputs thereto, and which controls the voltage of the control terminal of said third transistor element so that the voltage of said second node becomes substantially equal to that of said first node.