pca9634 NXP Semiconductors, pca9634 Datasheet - Page 19

• Manufacturer Part Number: pca9634
• Description: Pca9634 8-bit Fm I2c-bus Led Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA9634_4
Product data sheet
Fig 8. Brightness + Group Dimming signals
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)
3
3
256
4
4
7.8 Individual brightness control with group dimming/blinking
2
5
5
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
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)
Rev. 04 — 5 January 2007
256
(97.6 kHz)
40 ns = 10.24 s
40 ns, with ‘N’ defined in PWMx register).
N
with N = (0 to 255)
(PWMx Register)
40 ns
507
508
509
510
511
512
1
10.73
1
1
2
2
8-bit Fm+ I
Hz (8 bits, 256 steps) with
3
3
4
4
5
5
6
6
PCA9634
2
© NXP B.V. 2007. All rights reserved.
C-bus LED driver
7
7
8
8
9 10 11
002aab417
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