L16B45AG-R24-R datasheet(8/12 Pages) UTC

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L16B45A

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

8 of 12

www.unisonic.com.tw

QW-R102-071.a



APPLICATION INFORMATION

Constant Current

To design LED displays, UTC L16B45A provides nearly no variations in current from channel

to channel and from IC to IC. This can be achieved by:

1) The maximum current variation between channels is less than ±2.5%, and that between ICs is less than ±3%.

2) In addition, the current characteristic of output stage is flat and users can refer to the figure as shown below.

The output current can be kept constant regardless of the variations of LED forward voltages (VF). This performs as

a perfection of load regulation.

Adjusting Output Current

The output current of each channel (IOUT) is set by an external resistor, Rext. The relationship between IOUT and Rext

is shown in the following figure.

Also, the output current can be calculated from the equation:

VR-EXT=1.24V; IOUT=VR-EXT*( 1/Rext )x15; Rext=(VR-EXT/IOUT)x15

where Rext is the resistance of the external resistor connected to R-EXT terminal and VR-EXT is the voltage of R-EXT

terminal. The magnitude of current (as a function of Rext) is around 25mA at 744Ω and 10mA at 1860Ω.

L16B45AG-R24-R 数据表(PDF) 8 Page - Unisonic Technologies