| 摘要 |
<p>This invention relates to a current source circuit which is adapted to generate a current proportional to absolute temperature (PTAT) and which is able to operate at low supply voltages. The current source circuit includes two current mirrors (Q1,Q2;Q3,Q4), a start-up circuit (QS1,QS2,QS,Rs) and an output transisitor (Qo). The current of the start-up circuit flows through a resistor (Rc), which is part of one of the current mirrors, so as to provide a feedback for compensating for the variations in the supply voltage. An improved power supply rejection ratio (PSRR) is obtained. <IMAGE></p> |
