| 摘要 |
PURPOSE:To produce the reference voltage which has a fixed voltage difference that can be optionally set from a reference power supply voltage and also has the variable temperature characteristics of said voltage difference, by producing the voltage having a positive temperature coefficient from a reference voltage source of a band gap, etc. together with the voltage having the positive and negative temperature coefficients and then applying these two types of voltage in series for production of the reference voltage. CONSTITUTION:A reference voltage generating circuit flows a current 1 having a positive coefficient to a resistance R2 from a reference power supply to produce the voltage IR2 having a positive temperature coefficient under the control of a voltage source having no temperature characteristics such as a band gap voltage source. While the voltage VCE2 having a negative temperature coefficient is produced in series to the voltage IR2 from the current 1. These two types of voltage are added together to obtain the voltage DELTAV and the voltage Vout of a fixed level lower than the voltage V2 of the reference power supply by an amount equal to DELTAV is obtained. Here the ratio between the ratio IR2 and the VCE2 is changed to vary the temperature coefficient of the voltage DELTAV. Thus the temperature characteristics of the Vout can be changed. |
