Patent ID: 8922188
Filing Date: 2014-12-30
Classification: G05F,H03H

Abstract:
1. A low pass filter circuit comprising: a first PMOS transistor; a second PMOS transistor; a capacitor; a back gate voltage source connected between a back gate terminal and an input terminal of the low pass filter circuit; and a current source, the first PMOS transistor including a source connected to the input terminal, a drain connected to an output terminal of the low pass filter circuit, and a gate connected to one terminal of the current source, the second PMOS transistor including a source connected to the input terminal, and a gate and a drain connected to the one terminal of the current source, the capacitor being connected between the output terminal and a ground terminal, the current source having another terminal grounded, the first PMOS transistor and the second PMOS transistor connected to the back gate terminal and having the same substrate potential which is higher than a source potential of the first PMOS transistor and the second PMOS transistor, wherein a voltage at the back gate terminal is higher than that of the ground terminal by a predetermined amount.