| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical coupling device capable of inspecting optical element precisely and improving its reliability. <P>SOLUTION: The optical coupling device includes: a drive circuit connected to a light emitting element, a power source terminal, an input terminal, and a ground terminal, and driving the light emitting element and converting a digital signal to an optical signal; a clamp circuit connected to the input terminal; and a light receiving section converting the optical signal to an electrical signal and outputting. For an input voltage to the input terminal being within a range from a first voltage to a second voltage, the optical coupling device is allowed to enter an operation mode in which the drive circuit drives the light emitting element to convert the digital signal to the optical signal, and the electrical signal is outputted from the light receiving section. For an input voltage to the input terminal being outside the range from the first voltage to the second voltage, the optical coupling device is allowed to enter an inspection mode of the light emitting element, in which the drive circuit stops driving the light emitting element, the transistor of the clamp circuit is turned on, and a current generally equal or proportional to the clamp current is supplied to the light emitting element. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
