CONSTANT CURRENT CIRCUIT

• Main Author: SAKAGUCHI KAORU
• Format: Patent
• Language: English; Japanese
• Published: 19.03.2020
• Subjects: CONTROLLING; PHYSICS; REGULATING; SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES

To provide a constant current circuit capable of suppressing transient fluctuation of a constant current corresponding to fluctuation of a power supply voltage VDD when the power supply voltage fluctuates.SOLUTION: A constant current circuit comprises: a first current mirror circuit connected to a first power supply and including a first input transistor and a first output transistor of a first conductivity type; a second current mirror circuit including a second output transistor of a second conductivity type provided between the first input transistor and a second power supply and a second input transistor of the second conductivity type provided between the first output transistor and the second power supply; a resistor interposed between the second output transistor and the second power supply; and a capacitor whose one end is connected to the first power supply and whose other end is connected to a connection point between the second output transistor and the resistor.SELECTED DRAWING: Figure 1 【課題】電源電圧ＶＤＤが変動した際、この電源電圧の変動に対応した定電流の過渡的な変動を抑制することが可能な定電流回路を提供する。【解決手段】本発明は、第１電源に接続され、第１導電型の第１入力トランジスタ及び第１出力トランジスタを備える１カレントミラー回路と、第１入力トランジスタと第２電源との間に設けられた第２導電型の第２出力トランジスタ、及び第１出力トランジスタと第２電源との間に設けられた第２導電型の第２入力トランジスタを備える第２カレントミラー回路と、第２出力トランジスタと第２電源との間に介挿された抵抗と、一端が第１電源に接続され、他端が第２出力トランジスタ及び抵抗の接続点に接続されたコンデンサとを備える。【選択図】図１