pca9551bs3 NXP Semiconductors, pca9551bs3 Datasheet - Page 4

• Manufacturer Part Number: pca9551bs3
• Description: 8-bit I2c Led Driver With Programmable Blink Rates
• Manufacturer: NXP Semiconductors

NXP Semiconductors
6. Functional description
PCA9551_7
Product data sheet
6.1 Device address
6.2 Control register
Table 2.
[1]
Refer to
Following a START condition, the bus master must output the address of the slave it is
accessing. The address of the PCA9551 is shown in
internal pull-up resistors are incorporated on the hardware selectable address pins and
they must be pulled HIGH or LOW.
The last bit of the address byte defines the operation to be performed. When set to logic 1
a read is selected, while a logic 0 selects a write operation.
Following the successful acknowledgement of the slave address, the bus master will send
a byte to the PCA9551, which will be stored in the Control register.
The lowest 3 bits are used as a pointer to determine which register will be accessed.
Symbol
LED7
RESET
SCL
SDA
V
Fig 5. PCA9551 slave address
Fig 6. Control register
DD
HVQFN package die supply ground is connected to both V
connected to supply ground for proper device operation. For enhanced thermal, electrical, and board level
performance, the exposed pad needs to be soldered to the board using a corresponding thermal pad on the
board and for proper heat conduction through the board, thermal vias need to be incorporated in the PCB in
the thermal pad region.
Figure 1 “Block diagram of
Reset state: 00h
Pin
SO16, TSSOP16
12
13
14
15
16
Pin description
Rev. 07 — 23 February 2007
…continued
HVQFN16
10
11
12
13
14
Auto-Increment flag
8-bit I
1
0
1
0
fixed
PCA9551”.
2
C-bus LED driver with programmable blink rates
slave address
0
0
AI
Description
LED driver 7
reset input (active LOW)
serial clock line
serial data line
supply voltage
0
A2
0
selectable
hardware
register address
A1
B2
SS
Figure
pin and exposed center pad. V
A0 R/W
B1
002aac505
002aac506
B0
5. To conserve power, no
PCA9551
© NXP B.V. 2007. All rights reserved.
SS
pin must be
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