NCP5623

http://onsemi.com

9

Figure 5. Output Current Programmed Value ( ILED = F(Step) )

Step

35

25

20

15

10

5

0

0

15

30

30

10

25

5

20

PWM OPERATION

The built−in PWM are fully independent and can be

programmed to any value during the normal operation of the

NCP5623 chip. The PWM operate with five bits, yielding a

32 steps range to cover the full modulation (0 to 100%) of

the associated LED:

− PWM = $00

³ the associated LED is fully OFF,

whatever be the programmed ILED value

− PWM > $00 but < $1F

³ the brightness of the

associated LED is set depending upon the PWM

modulation value

− PWM = $1F

³ the associated LED is fully ON, the

current being the one defined by the ILED value.

Each PWM is programmable, via the I2C port as depicted,

at any time under any sequence arrangement as requested by

the end system’s designer. The PWM does not change the

ILED value, but merely modulate the ON/OFF ratio of the

associated LED. Each step of the PWM represent 100/31 =

3.225% of the full range, the clock being 2.1 kHz (typical).

Figure 6. Basic RGB Application

D1

C2

GND

C1

GND

SDA

R1

62 k

GND

SCL

+Vbat

+Vcc

MCU

I2C Port

Vdet

12

IREF

10

SDA

9

SCL

11

GND

6

LED3 3

LED2

4

LED1

5

U1

NCP5623

1 mF/6.3 V

1 mF/6.3 V

GND

Vbat

13

GND

2

IC NC NC IC

17

8 14

+5 V

5

2

6

4

3

1

R

G

B

LRTB−G6T