| 摘要 |
To provide an overcurrent protection apparatus for a load circuit which can detect an overcurrent accurately without being influenced by the offset voltage Voff of an amplifier (AMP1). When the amplifier (AMP1) has the offset voltage Voff which is a positive value (Voff>0), a current obtained by subtracting a current Ia from a current I1 flowing through a resistor R1 by conducting a current source IA is flown into a resistor R3. In contrast, when the amplifier (AMP1) has the offset voltage Voff which is a negative value (Voff<0), a voltage drop is generated at a resistor R2 by conducting a current source IB to thereby control so that a voltage Vds becomes same as the voltage generated at the resistor R1. Thus, since a voltage V3 generated at the resistor R3 becomes a voltage from which the influence of the offset voltage Voff is eliminated, it is possible to determine an overcurrent accurately by eliminating the influence of the offset voltage Voff.
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