LED constant current control chip

RM9003B

RM9003_Rev.19.01

www.reactor-micro.com

- 4-

Functional Block Diagram：

Application information：

In the linear circuit, the voltage at both ends of the IC is caused by the variation of the

input voltage (or the residual voltage in addition to the LED string),So that the power

consumption of IC changes, and in the whole circuit IC to assume the power of the

remaining power, constant LED series current, control the temperature of the LED lamp

characteristics.

Amount of selection：

Because the IC bear the residual voltage in the circuit, so in the design of the voltage of

the LED string closer to AC rectifier after the voltage, so that the whole circuit running

efficiency to achieve the best. Proposed chip power consumption is less than 1.5W.

The AC input voltage (V rms), single LED grain to drop (V), forward current (m A). Then

design the total number of LED grains：

N൥⩗=（ 쨰ᆋ×1.414− ）

V：ThevoltageICisassumedinthecircuit,thebiggerthevoltage,thegreaterthelossof

IC itself.

Constant current control function：

Chip built-in current limiting module, when the current flow through the chip is greater than

the chip determines the maximum value, the chip off D feet and S feet, so that the circuit is

in an instant off state, At the same time, once again, the D pin and the S pin are opened,

so that the current of the whole linear circuit is switched on and off, so that the current

flowing through the LED is constant.