ncp5623b ON Semiconductor, ncp5623b Datasheet - Page 10

• Manufacturer Part Number: ncp5623b
• Description: Triple Output I2c Controlled Rgb Led Driver
• Manufacturer: ON Semiconductor

NOTE:
30
25
20
15
10
5
0
0
Efficiency is measured with the three PWM equal to 100%
Figure 4. Output Current Programmed
5
Value ( ILED = F(Step) )
10
15
Figure 5. NCP5623B Typical Efficiency as a Function of the Vf
I2C Port
+Vcc
MCU
Step
GND
20
100
90
80
70
60
50
40
SDA
SCL
GND
GND
2.5
GND
1 mF/6.3 V
25
Vf = 2.85 V
C1
Figure 6. Basic RGB Application
62 k
R1
+Vbat
30
3.0
11
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7
9
6
8
Vbat
SDA
SCL
AGND
IREF
35
C1P
1
NCP5623B
V
10
220 nF
BAT
C3
3.5
U1
− PWM = $00 ³ the associated LED is fully OFF,
− PWM > $00 but < $1F ³ the brightness of the
− PWM = $1F ³ the associated LED is fully ON, the
PWM OPERATION
programmed to any value during the normal operation of the
NCP5623B chip. The PWM operate with five bits, yielding
a 32 steps range to cover the full modulation (0 to 100%) of
the associated LED:
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 100/32 =
3.125% of the full range, the clock being 2.1 kHz (typical).
(V)
Vf = 3.8 V
C1N
LED3
LED2
LED1
The built−in PWM are fully independent and can be
Each PWM is programmable, via the I2C port as depicted,
GND
whatever be the programmed ILED value
associated LED is set depending upon the PWM
modulation value
current being the one defined by the ILED value.
Vout
12
10
3
4
5
2
4.0
GND
1 mF/10 V
D2
C2
D3
D1
GND
4.5