| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a circuit for clamping an output voltage with excellent temperature characteristics. <P>SOLUTION: A clamp section 2 receives a reference voltage V<SB>REF</SB>from a reference voltage section 1 to perform clamping. A clamp voltage V<SB>CLP</SB>which is output to a clamp terminal Tc at the clamping, is defined by V<SB>CLP</SB>=(R3/R2)×V<SB>BEP</SB>+(V<SB>BEP</SB>-V<SB>BEN</SB>). In such a case, since an NPN transistor Q2 has the same temperature characteristics as that of a PNP transistor Q1, voltage variations of voltages between the bases and the emitters of both the bipolar transistors attended with a temperature change are canceled in the term of (V<SB>BEP</SB>-V<SB>BEN</SB>). Furthermore, by making a resistance value of a resistor R2 sufficiently greater than a resistance value of a resistor R3, a coefficient R3/R2 becomes small, thereby sufficiently reducing the voltage variations attended with the temperature change of V<SB>BEP</SB>in the term of (R3/R2)×V<SB>BEP</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
