pca9545ad NXP Semiconductors, pca9545ad Datasheet - Page 6

• Manufacturer Part Number: pca9545ad
• Description: 4-channel I2c Switch With Interrupt Logic And Reset
• Manufacturer: NXP Semiconductors

NXP Semiconductors
6. Functional description
PCA9545A_45B_45C_6
Product data sheet
6.1 Device address
Refer to
Following a START condition, the bus master must output the address of the slave it is
accessing. The address of the PCA9545A 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 slave address defines the operation to be performed. When set to
logic 1, a read is selected while a logic 0 selects a write operation.
The PCA9545BPW and PCA9545CPW are alternate address versions if needed for larger
systems or to resolve conflicts. The data sheet will reference the PCA9545A, but the
PCA9545B and PCA9545C function identically except for the slave address.
Fig 5. Slave address PCA9545A
Fig 6. Slave address PCA9545B
1
Figure 1 “Block diagram of
1
fixed
0
1
Rev. 06 — 19 March 2007
0
selectable
hardware
A1
1
A0 R/W
002aab835
4-channel I
1
PCA9545A/45B/45C”.
fixed
1
0
2
C-bus switch with interrupt logic and reset
0
Fig 7. Slave address PCA9545C
PCA9545A/45B/45C
selectable
hardware
A1
1
A0 R/W
002aab169
Figure
0
fixed
1
5. To conserve power, no
1
0
selectable
© NXP B.V. 2007. All rights reserved.
hardware
A1
002aab836
A0 R/W
6 of 28