US 12,445,113 B2
Low pass filter and semiconductor device
Hideyuki Sawai, Nagano (JP); and Tadashi Kurozo, Nagano (JP)
Assigned to ABLIC Inc., Nagano (JP)
Filed by ABLIC Inc., Nagano (JP)
Filed on Jan. 26, 2024, as Appl. No. 18/423,304.
Claims priority of application No. 2023-012407 (JP), filed on Jan. 31, 2023.
Prior Publication US 2024/0258996 A1, Aug. 1, 2024
Int. Cl. H03H 11/04 (2006.01); H03K 17/687 (2006.01)
CPC H03H 11/04 (2013.01) [H03K 17/687 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A low pass filter comprising: a first first-conductivity-type MOS transistor, an electrostatic capacitor, a buffer circuit including an operational amplifier circuit, a bias circuit, an input terminal, and an output terminal, wherein
the input terminal is connected to a source terminal of the first first-conductivity-type MOS transistor,
a drain terminal of the first first-conductivity-type MOS transistor is connected to a first terminal of the electrostatic capacitor, the output terminal, and an input terminal of the buffer circuit,
an output terminal of the operational amplifier circuit is connected to an inverting input terminal of the operational amplifier circuit and an output terminal of the buffer circuit,
the output terminal of the buffer circuit is connected to an input terminal of the bias circuit, and
an output terminal of the bias circuit is connected to a gate terminal of the first first-conductivity-type MOS transistor.