| 摘要 |
PROBLEM TO BE SOLVED: To reduce a loss in a current detection circuit and achieve a high-precision wide dynamic range with a simple configuration in a load drive device that controls current flowing through a load by a load drive circuit.SOLUTION: A load drive circuit, which is connected in series with a power supply path from a DC power supply to a load and has a semiconductor element Q1 that controls current flowing through the load by the ON/OFF operation on the basis of an external signal, comprises: a first drive circuit that performs the on/off driving of the semiconductor element Q1; and a current detection circuit 3 that converts the current into voltage according to current flowing through the semiconductor element Q1 and outputs the voltage. The current detection circuit 3 is constituted by a series circuit including a first current detection section Cd1 and a second current detection section Cd2. A second semiconductor element Qs1 is connected in parallel with the second current detection section Cd2. Furthermore, the current detection circuit 3 includes a current determination circuit 7 that switches between the first current detection section Cd1 and the second current detection section Cd2 according to the magnitude of a current detected by the first current detection section Cd1 so as to cause output of the current detection. |
