| 摘要 |
PURPOSE:To obtain a constant voltage circuit small in dependence on temperature by combining a band gap type constant current circuit and the base-emitter voltage of a transistor. CONSTITUTION:A constant voltage circuit consists of a constant current source 1, npn transistors TR 4 and TR 10, TR 7 and TR 8 having the equal emitter area, a TR 11 having a large emitter area and resistances 9 and 12. Then the corrector current IC of the TR 11 is equal to KT.ln(n)/R3, where (n) and R3 show the emitter area ratio between the TR 10 and TR 11 and the resistance value of the resistance 12. At the same time, the output voltage does not substnatially depend on the current value of the source 1 and is set at a fixed level. The temperature coefficient can be set at zero by a selecting properly the ratio between resistance 9 and 12. |
