9545A View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
Manufacturer
9545A Datasheet PDF : 32 Pages
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NXP Semiconductors
PCA9545A/45B/45C
4-channel I2C-bus switch with interrupt logic and reset
6. Functional description
Refer to Figure 1 “Block diagram of PCA9545A/45B/45C”.
6.1 Device address
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 Figure 5. To conserve power, no
internal pull-up resistors are incorporated on the hardware selectable address pins and
they must be pulled HIGH or LOW.
1 1 1 0 0 A1 A0 R/W
fixed
hardware
selectable
002aab169
Fig 5. Slave address PCA9545A
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 references the PCA9545A, but the
PCA9545B and PCA9545C function identically except for the slave address.
1 1 0 1 0 A1 A0 R/W
fixed
hardware
selectable
002aab835
Fig 6. Slave address PCA9545B
1 0 1 1 0 A1 A0 R/W
fixed
hardware
selectable
002aab836
Fig 7. Slave address PCA9545C
PCA9545A_45B_45C
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 5 May 2014
© NXP Semiconductors N.V. 2014. All rights reserved.
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