NSIC2050JBT3G

http://onsemi.com

5

APPLICATIONS INFORMATION

The CCR is a self biased transistor designed to regulate the

current through itself and any devices in series with it. The

device has a slight negative temperature coefficient, as

shown in Figure 2 – Tri Temp. (i.e. if the temperature

increases the current will decrease). This negative

temperature coefficient will protect the LEDS by reducing

the current as temperature rises.

The CCR turns on immediately and is typically at 20% of

regulation with only 0.5 V across it.

The device is capable of handling voltage for short

durations of up to 120 V so long as the die temperature does

not exceed 175

°C. The determination will depend on the

thermal pad it is mounted on, the ambient temperature, the

pulse duration, pulse shape and repetition.

AC Applications

The CCR is a DC device; however, it can be used with full

wave rectified AC as shown in application notes

AND8433/D

and

AND8492/D

and

design

notes

DN05013/D and DN06065/D. Figure 8 shows the basic

circuit configuration.

Figure 8. Basic AC Application

Single LED String

The CCR can be placed in series with LEDs as a High Side

or a Low Side Driver. The number of the LEDs can vary

from one to an unlimited number. The designer needs to

calculate the maximum voltage across the CCR by taking the

maximum input voltage less the voltage across the LED

string (Figures 9 and 10).

Figure 9.

Figure 10.