| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately detect load current by minimizing shift in an operating point without requiring excessive increase in an input range of a next-stage operational amplifier circuit or the like, for example.SOLUTION: A drive circuit is connected to a load (Rload) with a first current sensing resistor Rs1 inserted between a positive output (Vi+) of the drive circuit and a positive input (Vo+) of the load (Rload), and a second current sensing resistor Rs2 inserted between a negative input (Vo-) of the load (Rload) and a negative output (Vi-) of the drive circuit, such that first and second detection voltages Va, Vb are fed to a next-stage operational amplifier as a differential output (Va-Vb). A voltage between the negative input (Vo-) of the load (Rload) and the positive output (Vi+) of the drive circuit is divided into half by a first voltage divider (R1, R4) to be output as the first detection voltage (Va), while a voltage between the positive input (Vo+) of the load (Rload) and the negative output (Vi-) of the drive circuit is divided into half by a second voltage divider (R2, R3) to be output as the second detection voltage (Vb).</p> |
