| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a highly accurate differential amplifier section having a read-out margin even in an operation of comparatively lower voltage and also adaptive to variance in characteristics of composed elements. <P>SOLUTION: A power supply voltage Vdd having the voltage higher than a power supply voltage Vcc is supplied to a voltage supply node N0 of a voltage supply unit 90, thereby a value of (V<SB>GS</SB>-V<SB>T</SB>) becomes large to reduce a value of current error ΔI. A value of V<SB>GS</SB>of a transistor QP1a becomes large by changing the Vcc to Vdd, however, the transistor QP1a is considered as a mere resistor since a diode is connected to the the transistor QP1a, so that an increase in the value of V<SB>GS</SB>results an increase in voltage at both ends of the resistor, which is equal to make the resistance to high value provided that the current is regarded as constant. Thus, a voltage change (amplitude) of a node N1 with respect to a change in current flowing into the transistor QP1a is made larger as compared with variance in the threshold voltage of the transistor, and influence of current error based on the variance in transistor characteristic can be minimized accordingly. <P>COPYRIGHT: (C)2007,JPO&INPIT |
