描述 Description

The PCA9540B is a 1-of-2 bidirectional translating multiplexer, controlled via the I2C-bus.The SCL/SDA upstream pair fans out to two SCx/SDx downstream pairs, or channels.Only one SCx/SDx channel is selected at a time, determined by the contents of theprogrammable control register.
A power-on reset function puts the registers in their default state and initializes the I2C-busstate machine with no channels selected.
The pass gates of the multiplexer are constructed such that the VDD pin can be used tolimit the maximum high voltage that is passed by the PCA9540B. This allows the use ofdifferent bus voltages on each SCx/SDx pair, so that 1.8 V, 2.5 V or 3.3 V parts cancommunicate with 5 V parts without any additional protection. External pull-up resistorscan pull the bus up to the desired voltage level for this channel. All I/O pins are 5 Vtolerant.

特性 Features

1-of-2 bidirectional translating multiplexer
I2C-bus interface logic; compatible with SMBus standards
Channel selection via I2C-bus
Power-up with all multiplexer channels deselected
Low Ron 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, and 1000 V CDM perJESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
Packages offered: SO8, TSSOP8, XSON8