pca9634 NXP Semiconductors, pca9634 Datasheet - Page 12

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

NXP Semiconductors
PCA9634_4
Product data sheet
7.3.3 PWM0 to PWM7: Individual brightness control
7.3.4 GRPPWM: Group duty cycle control
Table 8.
Legend: * default value.
A 97 kHz fixed frequency signal is used for each output. Duty cycle is controlled through
256 linear steps from 00h (0 % duty cycle = LED output off) to FFh
(99.6 % duty cycle = LED output at maximum brightness). Applicable to LED outputs
programmed with LDRx = 10 or 11 (LEDOUT0 and LEDOUT1 registers).
Table 9.
Legend: * default value.
When DMBLNK bit (MODE2 register) is programmed with 0, a 190 Hz fixed frequency
signal is superimposed with the 97 kHz individual brightness control signal. GRPPWM is
then used as a global brightness control allowing the LED outputs to be dimmed with the
same value. The value in GRPFREQ is then a ‘Don’t care’.
General brightness for the 8 outputs is controlled through 256 linear steps from 00h
(0 % duty cycle = LED output off) to FFh (99.6 % duty cycle = maximum brightness).
Applicable to LED outputs programmed with LDRx = 11 (LEDOUT0 and LEDOUT1
registers).
When DMBLNK bit is programmed with logic 1, GRPPWM and GRPFREQ registers
define a global blinking pattern, where GRPFREQ contains the blinking period (from
24 Hz to 10.73 s) and GRPPWM the duty cycle (ON/OFF ratio in %).
duty cycle
Address
02h
03h
04h
05h
06h
07h
08h
09h
Address
0Ah
duty cycle
Register
PWM0
PWM1
PWM2
PWM3
PWM4
PWM5
PWM6
PWM7
PWM0 to PWM7 - PWM registers 0 to 7 (address 02h to 09h) bit description
GRPPWM - Group duty cycle control register (address 0Ah) bit description
Register
GRPPWM
=
=
GDC 7:0
-------------------------- -
IDC 7:0
------------------------
256
256
Bit
7:0
7:0
7:0
7:0
7:0
7:0
7:0
7:0
Rev. 04 — 5 January 2007
Bit
7:0
Symbol
IDC0[7:0]
IDC1[7:0]
IDC2[7:0]
IDC3[7:0]
IDC4[7:0]
IDC5[7:0]
IDC6[7:0]
IDC7[7:0]
Symbol
GDC[7:0]
Access Value
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Access Value
R/W
0000 0000* PWM0 Individual Duty Cycle
0000 0000* PWM1 Individual Duty Cycle
0000 0000* PWM2 Individual Duty Cycle
0000 0000* PWM3 Individual Duty Cycle
0000 0000* PWM4 Individual Duty Cycle
0000 0000* PWM5 Individual Duty Cycle
0000 0000* PWM6 Individual Duty Cycle
0000 0000* PWM7 Individual Duty Cycle
1111 1111
8-bit Fm+ I
Description
Description
GRPPWM register
PCA9634
2
© NXP B.V. 2007. All rights reserved.
C-bus LED driver
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