JPH0165521U

JPH0165521U -

Info

Publication number: JPH0165521U
Application number: JP1987160448U
Authority: JP
Priority date: 1987-10-20
Filing date: 1987-10-20
Publication date: 1989-04-26

Description

[Brief explanation of the drawing]

第１図から第４図までが本考案に関し、内第１
図は本考案によるリセツト回路の原理回路図、第
２図はその主な信号の動作波形図、第３図および
第４図は本考案のそれぞれ異なる実施例の回路図
である。第５図以降は従来技術に関し、第５図お
よび第６図は従来のリセツト回路の回路図、第７
図はその主な信号の動作波形図である。図におい
て、１：リセツト回路、２：リセツト対象回路、１
０：リセツトトランジスタ、１１：抵抗、２０：
しきい値回路ないしはしきい値回路としての電流
ミラー回路、２１：トランジスタ、２２：抵抗、
２３：ダイオード、２４，２５：抵抗、２６：電
流ミラー回路の基準トランジスタ、２７：電流ミ
ラー回路の従動トランジスタ、３０：リセツトト
ランジスタ、３１：抵抗、４０：しきい値回路な
いしはしきい値回路としての電流ミラー回路、４
１：トランジスタ、４２：抵抗、４３：ツエナダ
イオード、４４，４５：抵抗、４６：電流ミラー
回路の基準トランジスタ、４７：電流ミラー回路
の従動トランジスタ、Ｆ：浮動状態、Ｒ１，Ｒ２
：抵抗値、ＲＳ：リセツト信号、ｔ０〜ｔ７：時
刻、Ｖ１：第１の電圧、Ｖ２：第２の電圧、ｖ：
リセツトトランジスタのベース・エミツタ間電圧
、ｖｂ：しきい値回路の出力トランジスタのベー
ス・エミツタ間電圧ないしは電流ミラー回路の基
準トランジスタのベース・エミツタ間電圧、ｖｄ
：ダイオードの順方向電圧、Ｖｔ：しきい値回路
の動作しきい値、ｖｚ：ツエナダイオードのツエ
ナ電圧、である。 Figures 1 to 4 relate to the present invention, of which Figure 1
2 is a diagram showing the principle of the reset circuit according to the present invention, FIG. 2 is an operational waveform diagram of its main signals, and FIGS. 3 and 4 are circuit diagrams of different embodiments of the present invention. Figure 5 and subsequent figures relate to the prior art, Figures 5 and 6 are circuit diagrams of conventional reset circuits, and Figure 7
The figure is an operation waveform diagram of the main signals. In the figure, 1: reset circuit, 2: reset target circuit, 1
0: Reset transistor, 11: Resistor, 20:
Threshold circuit or current mirror circuit as threshold circuit, 21: transistor, 22: resistor,
23: Diode, 24, 25: Resistor, 26: Reference transistor of current mirror circuit, 27: Driven transistor of current mirror circuit, 30: Reset transistor, 31: Resistor, 40: Threshold circuit or threshold circuit Current mirror circuit, 4
1: Transistor, 42: Resistor, 43: Zener diode, 44, 45: Resistor, 46: Reference transistor of current mirror circuit, 47: Driven transistor of current mirror circuit, F: Floating state, R1, R2
: resistance value, RS: reset signal, t0 to t7: time, V1: first voltage, V2: second voltage, v:
Base-emitter voltage of the reset transistor, vb: Base-emitter voltage of the output transistor of the threshold circuit or base-emitter voltage of the reference transistor of the current mirror circuit, vd
: forward voltage of the diode, Vt: operating threshold of the threshold circuit, vz: Zener voltage of the Zener diode.

Claims

[Claims for Utility Model Registration] 1. A reset circuit that resets a circuit operating under a second voltage when the value of the first voltage falls below a predetermined threshold, the reset circuit comprising: A reset transistor receives a first voltage between its base and emitter through a resistor and the collector potential is derived as a reset signal, and a reset transistor receives a first voltage and operates when the value is above a threshold value to control the base current of the reset transistor. 1. A reset circuit comprising a threshold circuit which bypasses the reset signal and floats the reset signal as its collector potential. 2. In the circuit according to claim 1 of the utility model registration, the threshold circuit receives the first voltage between the base and emitter via the resistor and the threshold adjustment element, and the collector is connected to the base of the reset transistor. A reset circuit comprising connected transistors. 3 Utility Model Registration In the circuit described in claim 1, the threshold circuit receives the first voltage through a resistor to the reference current side transistor, and the collector of the driven current side transistor is connected to the base of the reset transistor. A reset circuit characterized in that it is a current mirror circuit.