Operational amplifier
AssigneeRohm Co., Ltd.
InventorsHiroyuki Makimoto, Yusuke Yoshii, Yuki Inoue
Life of this patent
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Abstract
An operational amplifier 1 comprises transistors Q1 and Q2 forming an input stage, and input resistors R1 and R2 which form a filter together with parasitic capacitors C1 and C2 accompanying the transistors Q1 and Q2. Resistance values R of the resistors R1 and R2 may be set to R=1/(2π·fc·C), where C is the capacitance value of each of the parasitic capacitors C1 and C2, and fc is the target cutoff frequency of the filter. The operational amplifier 1 may also include a power supply resistor R0 which forms a filter together with a parasitic capacitor C0 accompanying a power supply line.
Claims20
A semiconductor device comprising:
- an operational amplifier;
- a reference current setting portion configured to set a reference current of the operational amplifier;
- a power supply line configured to be laid between a power supply terminal and each of the operational amplifier and the reference current setting portion;
- a ground line configured to be laid between a ground terminal and each of the operational amplifier and the reference current setting portion;
- and
- a reference current setting line configured to be laid between the operational amplifier and the reference current setting portion,
- wherein the operational amplifier comprises:
- a transistor configured to form an input stage;
- and
- an input resistor configured to form a filter together with a parasitic capacitor of the transistor,
- wherein in plan view of the semiconductor device, the power supply line and the reference current setting line are laid one above another so as to partially overlap with each other, and
- wherein, in plan view of the semiconductor device, a part of the reference current setting line that overlaps with the power supply line is laid in a grid pattern.
A semiconductor device comprising:
- an operational amplifier;
- a reference current setting portion configured to set a reference current of the operational amplifier;
- a power supply line configured to be laid between a power supply terminal and each of the operational amplifier and the reference current setting portion;
- a ground line configured to be laid between a ground terminal and each of the operational amplifier and the reference current setting portion;
- and
- a reference current setting line configured to be laid between the operational amplifier and the reference current setting portion,
- wherein the operational amplifier comprises:
- a transistor configured to form an input stage;
- and
- an input resistor configured to form a filter together with a parasitic capacitor of the transistor, and
- wherein the semiconductor device further comprises a shield member configured to be inserted between the power supply line and each of another wiring and another element.
Dependencies are inferred from the claim text.