| 摘要 |
PURPOSE:To equalize a flow-in current from a charge pump to a low-pass filter and a flow-out current from the low-pass filter by setting them with one resistor. CONSTITUTION:A current value I is set with the voltage drop VBE of a diode 51 and a resistor 52, and the current value I is used as the flow-in current value to a low-pass filter 3 and also as the flow-out current value from the low-pass filter 3. Also, a degree of freedom is given to the output voltage setting value of the low-pass filter 3 using only a differential switch circuit and a current mirror circuit. Each pair of transistors 57 and 58, and transistors 65 and 66 constitutes a differential amplifier respectively, and transistors 59 and 60, and transistors 61 and 62 constitute current mirror circuits.
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