CONSTANT CURRENT CIRCUIT
PURPOSE:To provide the constant current circuit which has excellent temperature characteristics without being affected by hFE of a transistor(TR). CONSTITUTION:The constant current circuit which allows the currents I1 and I2 from a current mirror circuit 1 to flow through a current mirror circuit 2...
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| Format: | Patent |
| Sprache: | eng |
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| Zusammenfassung: | PURPOSE:To provide the constant current circuit which has excellent temperature characteristics without being affected by hFE of a transistor(TR). CONSTITUTION:The constant current circuit which allows the currents I1 and I2 from a current mirror circuit 1 to flow through a current mirror circuit 2 inhibits the former base current from being sent directly to the latter, namely, is constituted by connecting a diode-connected TR Q6 which sends out the base current to a TR Q7 other than TRs Q3 and Q4 constituting the current mirror circuit 2. Consequently, the influence of the hFE of the respective TRs on the constant currents I is substantially removed, which is evident when an NPN TR is used as the TR Q7. Further, an actuation circuit which operates in power-ON operation to securely send the base current of the current mirror circuit 1 is added. |
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