A8180
AiT Semiconductor Inc.
www.ait-ic.com
LED LIGHTING DRIVER
HIGH BRIGHTNESS LED DRIVER WITH INTERNAL SWITCH
Setting Nominal Average Output Current with External Resistor RS
The nominal average output current in the LED(s) is determined by the value of the external current sense
resistor (RS) connected between VIN and ISENSE and is given by:
0.1
IOUT
=
RS
This equation is valid when ADJ pin is float or applied with a voltage higher than 1.2V (must be less than or
equal to 5V). Actually, RS sets the maximum average current which can be adjusted to a less one by dimming.
The table below gives values of nominal average output current for several preferred values of current setting
resistor (RS) in the typical application circuit shown on page 1.
Nominal Average Output Current (mA)
RS(Ω)
0.1
1000
760
667
333
0.13
0.15
0.3
Output Current Adjustment by External DC Control
The ADJ pin can be driven by an external dc voltage (VADJ), as shown, to adjust the output current to a value
below the nominal average value defined by RS.
REV3.0
- APR 2010 RELEASED, JAN 2017 UPDATED -
- 11 -
AITSEMI [ AiT Semiconductor ]
