NCP5623C View Datasheet(PDF) - ON Semiconductor

Part Name

Description

MFG CO.

NCP5623C

Triple Output I2C Controlled RGB LED Driver

ON Semiconductor 

NCP5623C

30

PWM OPERATION

The built−in PWM are fully independent and can be

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programmed to any value during the normal operation of the

NCP5623C chip. The PWM operate with five bits, yielding

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

the associated LED:

15

− PWM = $00 ³ the associated LED is fully OFF,

whatever be the programmed ILED value

10

− PWM > $00 but < $1F ³ the brightness of the

associated LED is set depending upon the PWM

5

modulation value

− PWM = $1F ³ the associated LED is fully ON, the

0

0

5

10

15

20

25

30

35

current being the one defined by the ILED value.

Step

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

at any time under any sequence arrangement as requested by

Figure 4. Output Current Programmed

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

Value ( ILED = F(Step) )

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

associated LED. Each step of the PWM represent 100/32 =

3.125% of the full range, the clock being 2.1 kHz (typical).

100

90

Vf = 2.85 V

80

Vf = 3.8 V

70

60

50

40

2.5

3.0

3.5

4.0

4.5

VBAT (V)

Figure 5. NCP5623C Typical Efficiency as a Function of the Vf

NOTE: Efficiency is measured with the three PWM equal to 100%

+Vcc

+Vbat

1 mF/6.3 V

C1

GND

11

MCU

SDA

7

I2C Port SCL

9

6

GND

GND R1 8

62 k

GND

C3

220 nF

1

12

C1P

Vbat

C1N 10

Vout

SDA

SCL

LED3 3

LED2 4

AGND

IREF

LED1 5

GND 2

C2

1 mF/10 V

GND

D3

D2

D1

NCP5623C

U1

GND

Figure 6. Basic RGB Application

http://onsemi.com

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