pca9635 NXP Semiconductors, pca9635 Datasheet - Page 18

• Manufacturer Part Number: pca9635
• Description: Pca9635 16-bit Fm I2c-bus Led Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Table 15.
[1]
[2]
PCA9635_5
Product data sheet
LEDOUT
11
individual +
group
dimming/blinking
Fig 6. Brightness + Group Dimming signals
When OE = 1, LED output state is controlled only by OUTNE[1:0] bits (MODE2 register).
External pull-up or LED current limiting resistor connects LEDn to V
1
1
Brightness Control signal (LEDn)
Group Dimming signal
resulting Brightness + Group Dimming signal
Minimum pulse width for LEDn Brightness Control is 40 ns.
Minimum pulse width for Group Dimming is 20.48 s.
When M = 1 (GRPPWM register value), the resulting LEDn Brightness Control + Group Dimming signal will have 2 pulses
of the LED Brightness Control signal (pulse width = N
This resulting Brightness + Group Dimming signal above shows a resulting Control signal with M = 4 (8 pulses).
2
2
(GRPPWM Register)
M
with M = (0 to 255)
Output transistors based on LEDOUT registers, INVRT and OUTDRV bits when OE = 0
3
3
256
4
4
7.8 Individual brightness control with group dimming/blinking
2
5
5
INVRT
0
0
1
1
40 ns
6
6
A 97 kHz fixed frequency signal with programmable duty cycle (8 bits, 256 steps) is used
to control individually the brightness for each LED.
On top of this signal, one of the following signals can be superimposed (this signal can be
applied to the 4 LED outputs):
7
7
•
•
256
8
8
OUTDRV
0
1
0
1
A lower 190 Hz fixed frequency signal with programmable duty cycle (8 bits,
256 steps) is used to provide a global brightness control.
A programmable frequency signal from 24 Hz to
programmable duty cycle (8 bits, 256 steps) is used to provide a global blinking
control.
9 10 11 12
2
256
40 ns = 5.24 ms (190.7 Hz)
Upper transistor
(V
off
individual PWM
(non-inverted)
off
individual PWM
(inverted)
DD
to LEDn)
Rev. 05 — 22 March 2007
256
(97.6 kHz)
40 ns = 10.24 s
40 ns, with ‘N’ defined in PWMx register).
Lower transistor
(LEDn to V
individual + group
PWM
(non-inverted)
individual PWM
(non-inverted)
individual + group
PWM (inverted)
individual PWM
(inverted)
N
with N = (0 to 255)
(PWMx Register)
40 ns
DD
507
.
508
509
SS
)
510
511
LEDn state
V
values
V
high-Z
(1
V
(1
512
SS
SS
DD
1
10.73
or high-Z
or V
GRPPWM) values
or V
GRPPWM) values
1
1
[2]
2
2
16-bit Fm+ I
DD
SS
or V
Hz (8 bits, 256 steps) with
3
3
= PWMx or GRPPWM values
= (1
SS
[2]
4
4
= PWMx or GRPPWM
= (1
5
5
PWMx) or
6
6
PCA9635
2
PWMx) or
© NXP B.V. 2007. All rights reserved.
C-bus LED driver
[1]
7
7
…continued
8
8
9 10 11
002aab417
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