PCA9544A

General description

The PCA9544A is a 1-of-4 bidirectional translating multiplexer, controlled via the I²C-bus. The SCL/SDA upstream pair fans out to four SCx/SDx downstream pairs, or channels. Only one SCx/SDx channel is selected at a time, determined by the contents of the programmable control register. Four interrupt inputs, INT0 to INT3, one for each of the SCx/SDx downstream pairs, are provided. One interrupt output, INT, which acts as an AND of the four interrupt inputs, is provided.

A power-on reset function puts the registers in their default state and initializes the I²C-bus state machine with no channels selected.

The pass gates of the multiplexer are constructed such that the V_DD pin can be used to limit the maximum high voltage which will be passed by the PCA9544A. This allows the use of different bus voltages on each SCx/SDx 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-4 bidirectional translating multiplexer
• I²C-bus interface logic; compatible with SMBus
• 4 active LOW interrupt inputs
• Active LOW interrupt output
• 3 address pins allowing up to 8 devices on the I²C-bus
• Channel selection via I²C-bus
• Power-up with all multiplexer channels deselected
• Low R_on switches
• 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
• Three packages offered: SO20, TSSOP20 and HVQFN20

Products/packages

Quality/reliability/chemical content

Quality and reliability disclaimer

Pricing/ordering/availability

Block diagrams/pinning

Design support

Application Notes

AN262_2; PCA954X FAMILY OF I²C / SMBus MULTIPLEXERS and SWITCHES (2004-10-01)

Support Documents

UM10204_3; I2C-bus specification and user manual (2007-06-26)

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

Parametrics/similar products

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer