TEST METHOD AND TEST CIRCUIT

摘要

PURPOSE: To provide the test circuit of a simple and inexpensive laser diode drive circuit without using any laser diode and any photo-diode. CONSTITUTION: An emitter of a pnp transistor 5 allowing current to flow in response to applied voltage for a base is connected to a positive power source through a resistor 6. The collector of the transistor 5 is connected to the terminal A at the side of a light receiving element of a drive circuit, one terminal of a resistor 7 is coupled to the positive power source, the other terminal of the resistor 7 is connected to the base of the transistor 5 and the terminal B at the side of a light emitting element. A light emitting element drive circuit is tested by changing the resistor 6 or 7.