Signal converting circuit

A signal conversion circuit, which takes as input differential voltage signals to a first input terminal and a second input terminal, converts the common-mode voltage level of the differential voltage signals, and outputs differential voltage signals, with said converted common-mode voltage level, from a first output terminal and a second output terminal, comprising:

• a first resistor, one end of which is connected to a low-potential side of a power supply, and the other end of which is connected to said first output terminal;
• a second resistor, one end of which is connected to said low-potential side of the power supply, and the other end of which is connected to said second output terminal;
• a first PMOS transistor, having a drain electrode connected to said first output terminal, a gate electrode connected to said second input terminal, and a source electrode;
• a second PMOS transistor, having a drain electrode connected to said second output terminal, a gate electrode connected to said first input terminal, and a source electrode;
• a third PMOS transistor, having a drain electrode connected to said first output terminal, a gate electrode to which a first bias voltage is input, and a source electrode;
• a fourth PMOS transistor, having a drain electrode connected to said second output terminal, a gate electrode to which said first bias voltage is input, and a source electrode;
• a first NMOS transistor, having a source electrode connected to said source electrode of said third PMOS transistor, a gate electrode connected to said first input terminal, and a drain electrode connected to a high-potential side of the power supply;
• a second NMOS transistor, having a source electrode connected to said source electrode of said fourth PMOS transistor, a gate electrode connected to said second input terminal, and a drain electrode connected to said high-potential side of the power supply;
• and
• a current source, which is provided between the source electrode of said first PMOS transistor and the source electrode of said second PMOS transistor on the one hand, and said high-potential side of the power supply on the other, and which generates a constant current.

A signal conversion circuit, which takes as input differential voltage signals to a first input terminal and a second input terminal, converts the common-mode voltage level of the differential voltage signals, and outputs differential voltage signals, with said converted common-mode voltage level, from a first output terminal and a second output terminal, comprising:

• a first resistor, one end of which is connected to a first power supply potential, and the other end of which is connected to said first output terminal;
• a second resistor, one end of which is connected to said first power supply potential, and the other end of which is connected to said second output terminal;
• a first transistor, having a first electrode connected to said first output terminal, a second electrode connected to said second input terminal, and a third electrode;
• a second transistor, having a first electrode connected to said second output terminal, a second electrode connected to said first input terminal, and a third electrode;
• a third transistor, having a first electrode connected to said first output terminal, a second electrode to which a first bias voltage is input, and a third electrode;
• a fourth transistor, having a first electrode connected to said second output terminal, a second electrode to which said first bias voltage is input, and a third electrode;
• a fifth transistor, having a first electrode connected to said third electrode of said third transistor, a second electrode connected to said first input terminal, and a third electrode connected to a second power supply potential;
• a sixth transistor, having a first electrode connected to said third electrode of said fourth transistor, a second electrode connected to said second input terminal, and a third electrode connected to said second power supply potential;
• and
• a current source, which is provided between the third electrode of said first transistor and the third electrode of said second transistor on the one hand, and said second power supply potential on the other, and which generates a constant current.