Patent ID: 11871492
Assignee: ROHM CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A light emitting element drive device comprising:
a driving circuit configured to supply a variable drive current to a light emitting unit including one or more light emitting elements, so that the light emitting unit is configured to emit light;
a drive reference voltage generation circuit configured to generate a drive reference voltage defining an upper limit value of the drive current, and supply the drive reference voltage to the driving circuit; and
a specific external terminal, wherein an external resistor is connectable between the specific external terminal and ground, outside the light emitting element drive device, and
wherein:
the drive reference voltage generation circuit is operable selectively in a first mode to generate the drive reference voltage regardless of the state of the specific external terminal, or a second mode to generate the drive reference voltage in accordance with a second mode current through the specific external terminal, and
the light emitting element drive device is configured such that when the drive reference voltage generation circuit operates in the second mode in a state where the external resistor is connected between the specific external terminal and ground, the drive reference voltage generation circuit supplies the second mode current to the external resistor through the specific external terminal, so as to generate the drive reference voltage in accordance with a magnitude of the second mode current or the voltage generated by the external resistor.