| 摘要 |
PURPOSE: To reduce power consumption and to decrease production costs by providing a cascade bias generator, which has an N-channel transistor for generating a bias voltage, and a current source for supplying a DC power source. CONSTITUTION: A cascade bias generator 50 generates a bias voltageNBIAS1 while using a resistor 51. A maximum output voltage amplitude in a high current mirror output impedance is maintained by keeping the voltage drop of a resistor 51 to be equal to the value obtained by adding a threshold voltage VT of a transistor 64 to the voltage of the cascade N-channel transistor 64 and by subtracting a VT of N-channel transistor 63. The voltage drop of the resistor 51 is less than several hundreds of volts. Therefore, the resistor 51 can be mounted on an integrated circuit with the resistance value easy for manufacture, within a range from about 100Ωto about 20 kΩin order to supply a cascade bias voltage optimum for allowing a current to flow within a range of about 10μA to 1 mA.
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