Light-emitting element driving device and light-emitting system

Abstract

An LED driver (1A) includes: a driving circuit (10[i]) that supplies a variable driving current to a light-emitting unit having one or more LEDs, enabling the light-emitting unit to emit light; and a driving reference voltage generation circuit (20A) that generates a driving reference voltage (V) that defines an upper limit value of the driving current. DREF ), and the driving reference voltage (V DREF ) supplied to the drive circuit; and a specific external terminal (EX) ISET ), the specific external terminal (EX) ISET It can be connected to an external resistor (R) EX_A The drive reference voltage generation circuit selectively operates in a first mode to generate the drive reference voltage regardless of the state of the particular external terminal, or operates in a second mode to generate the drive reference voltage based on the second mode current ((I) passing through the particular external terminal). EX_A The driving reference voltage is generated.

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