ncp5623a ON Semiconductor, ncp5623a Datasheet - Page 9

• Manufacturer Part Number: ncp5623a
• Description: Triple Output I2c Controlled Rgb Led Driver
• Manufacturer: ON Semiconductor

encoded into the second byte of the I2C transaction: see
Table 1.
B5 = 1), the output current is straightforwardly set up to the
level defined by the contain of the related register upon
acknowledge of the output current byte.
the start and end output current range: since the IPEAK
value is encoded in the Bits[4:0] binary scale, a maximum
of 31 steps is achievable during a gradual dimming
operation.
the chip according to the equation:
step was 5 and the new one is 15, then we will have 10 steps
to run between the actual location to the end value. If the
NOTE:
Table 3. Output Current Programmed Value (ILED = F(Step))
Table 2. Basic Programming Sequences
The dimming is built with 30 steps and the time delay
When the gradual dimming is deactivated (B7 = B6 = 0,
The number of step for a given sequence, depends upon
The number of steps will be automatically recalculated by
Nstep = | existing step position − new step position |
As an example, assuming the previously programmed
I2C Address
0 / $00
1 / $01
2 / $02
3 / $03
4 / $04
5 / $05
6 / $06
7 / $07
8 / $08
Step
$70
$70
$70
$70
$70
$70
$70
$70
The table assumes I
ILED (mA)
COMMAND Bits[7:0]
0.92
0.95
0.98
1.02
1.06
1.10
1.15
1.20
0
000X XXXX
0010 0000
0100 0000
0110 0000
1000 0000
1010 0000
1100 0000
0101 1111
1001 1111
1110 0000
0011 1111
0111 1111
1011 1111
1101 1111
1111 1111
REF
= 11.5 mA
10 / $0A
12 / $0C
13 / $0D
14 / $0E
11 / $0B
15 / $0F
16 / $10
17 / $11
9 / $09
Step
Set Up the Gradual Dimming time
Set Up the IEND Downward
Set Up the IEND Upward
Set Up the ILED current
and run the sequence
ILED (mA)
System Shut Down
Set Up the PWM1
Set Up the PWM2
Set Up the PWM3
1.25
1.31
1.38
1.45
1.53
1.62
1.72
1.84
1.97
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Operation
9
new output current data byte is send to the NCP5623A . At
this point, the brightness sequence takes place when the new
data byte is acknowledged by the internal I2C decoder. Since
the six registers are loaded on independent byte flow
associated to the I2C address, any parameter of the
NCP5623A chip can be updated ahead of the next function
as depicted in Table 2.
timing was set at 16 ms, the total gradual dimming sequence
will be 160 ms.
Upward or Downward), one shall send the appropriate
register before to activate the sequence as depicted below:
1010 1111 ³
sequence with 24 ms/step, the end IPEAK current being
(IREF * 2400) / (31 − 16) mA.
1100 0001 ³
sequence with 32 ms/step, the end IPEAK current being
(IREF * 2400) / (31 − 1) mA.
26 / $1A
18 / $12
19 / $13
20 / $14
21 / $15
22 / $16
23 / $17
24 / $18
25 / $19
Step
The gradual dimming sequence must be set up before a
To select the direction of the gradual dimming (either
Bits[4:0] contain the IMAX value as defined by the
ILED (mA)
2.12
2.30
2.50
2.76
3.06
3.45
3.94
4.60
5.52
1110 0100 ³
Bits[4:0] contain the PWM value
Bits[4:0] contain the PWM value
Bits[4:0] contain the PWM value
Bits[4:0] contain the IEND value
Bits[4:0] contain the IEND value
Bits[4:0] contain the TIME value
1110 0011 ³
Bits[4:0] are irrelevant
ILED register
DWNWRD
UPWARD
Iref value
28 / $1C
29 / $1D
30 / $1E
31 / $1F
27 $1B
PWM1
PWM2
PWM3
GRAD
Note
Step
select the DOWNWARD
select an UPWARD
ILED (mA)
13.80
27.60
27.60
6.90
9.20