CAT9552WI Datasheet, PDF (12/17 Pages) ON Semiconductor – 16-Channel I2C-bus LED Driver with Programmable Blink Rate

CAT9552
APPLICATION INFORMATION
Programming Example
The following programming sequence is an
example how to set:
– LED0 to LED3: ON
– LED4 to LED7: Blink at 1Hz with a 50% duty
cycle (Blink 0)
– LED8 to LED11: Blink at 4Hz with a 20% duty
cycle (Blink 1)
– LED12 to LED15: OFF
5V
Command Description
1 START
2 Send Slave address, A0-A2 = low
3 Command Byte: AI=”1”; PSC0 Addr
Set Blink 0 at 1Hz, T_Blink1 =
4 (PSC0+1)/44 = 1
Write PSC0 = 43
Set PWM0 duty cycle to 50%
5 (256-PWM0) / 256 = 0.5
Write PWM0=128
Set Blink 1 at 4Hz, T_Blink1 =
6 (PSC1+1)/44 = 0.25
Write PSC1 = 10
Set PWM1 duty cycle to 25%
7 (256-PWM1) / 256 = 0.25
Write PWM1=192
8 Write LS0: LED0 to LED3 = ON
9 Write LS1: LED4 to LED7 at Blink0
10 Write LS2: LED8 to LED11 at Blink1
11 Write LS3: LED12 to LED15 = OFF
12 STOP
5V
I²C Data
C0h
12h
2Bh
80h
0Ah
C0h
00h
AAh
FFh
55h
V_CC
SDA
SCL
RESET
GND
I²C/SMBus MASTER
10kΩ (x 3)
SDA
V_CC
LED0
LED1
LED2
SCL
LED3
LED4
RESET
LED5
LED6
LED7
CAT9552
LED8
LED9
A2
LED10
A1
LED11
A0
LED12
V_SS
LED13
LED14
LED15
Note: LED0 to LED11 are used as LED drivers and LED12 to LED15 are used as regular GPIOs.
GPIOs
Figure 10. Typical Application
Doc. No. MD-9005 Rev B
12
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Characteristics subject to change without notice