PCA9547

General description

The PCA9547 is an octal bidirectional translating multiplexer controlled by the I²C-bus. The SCL/SDA upstream pair fans out to eight downstream pairs, or channels. Only one SCx/SDx channel can be selected at a time, determined by the contents of the programmable control register. The device powers up with Channel 0 connected, allowing immediate communication between the master and downstream devices on that channel.

An active LOW reset input allows the PCA9547 to recover from a situation where one of the downstream I²C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets the I²C-bus state machine causing all the channels to be deselected, except Channel 0 so that the master can regain control of the bus.

The pass gates of the multiplexers are constructed such that the V_DD pin can be used to limit the maximum high voltage which will be passed by the PCA9547. This allows the use of different bus voltages on each pair, so that 1.8 V, 2.5 V, or 3.3 V parts can communicate with 5 V parts without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5 V tolerant.

Features

• 1-of-8 bidirectional translating multiplexer
• I²C-bus interface logic; compatible with SMBus standards
• Active LOW RESET input
• 3 address pins allowing up to 8 devices on the I²C-bus
• Channel selection via I²C-bus, one channel at a time
• Power-up with all channels deselected except Channel 0 which is connected
• Low R_on multiplexers
• Allows voltage level translation between 1.8 V, 2.5 V, 3.3 V and 5 V buses
• No glitch on power-up
• Supports hot insertion
• Low standby current
• Operating power supply voltage range of 2.3 V to 5.5 V
• 5 V tolerant inputs
• 0 Hz to 400 kHz clock frequency
• ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101
• Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
• Packages offered: SO24, TSSOP24, HVQFN24

Products/packages

Quality/reliability/chemical content

Quality and reliability disclaimer

Pricing/ordering/availability

Applications

Related applications
Intelligent washing machine

Block diagrams/pinning

Design support

Application Notes

AN10441; Level shifting techniques in I2C-bus design (2007-06-20)

Support Documents

UM10206; I2C Demonstration Board 2005-1 Quick Start Guide (2006-06-13)

UM10204; I2C-bus specification and user manual (2007-06-26)

web; IBIS and HSPICE Model ()

75016529; NXP 2-, 4-, and 8-channel I²C/SMBus muxes and switches PCA954x (2008-07-01)

Parametrics/similar products

Similar products
PCA9547 links to the similar products page containing an overview of products that are similar in function or related to the type number(s) as listed on this page. The similar products page includes products from the same catalog tree(s), relevant selection guides and products from the same functional category.

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer