TCA9546A Datasheet, PDF (1/31 Pages) Texas Instruments – Low Voltage 4-Channel I2C and SMBus Switch with Reset Function

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TCA9546A
SCPS205A – APRIL 2014 – REVISED FEBRUARY 2015
TCA9546A Low Voltage 4-Channel I²C and SMBus Switch with Reset Function
1 Features
•1 1-of-4 Bidirectional Translating Switches
• I²C Bus and SMBus Compatible
• Active-Low Reset Input
• Three Address Pins, Allowing up to Eight
TCA9546A Devices on the I²C Bus
• Channel Selection Via I²C Bus, in Any
Combination
• Power-up With All Switch 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 1.65 V
to 5.5 V
• 5.5 V Tolerant Inputs
• 0 to 400-kHz Clock Frequency
• Latch-Up Performance Exceeds 100 mA Per
JESD 78
• ESD Protection Exceeds JESD 22
– 4000-V Human-Body Model (A114-A)
– 1500-V Charged-Device Model (C101)
2 Applications
• Servers
• Routers (Telecom Switching Equipment)
• Factory Automation
• Products With I²C Slave Address Conflicts (e.g.
Multiple, Identical Temp Sensors)
3 Description
The TCA9546A is a quad bidirectional translating
switch controlled via the I²C bus. The SCL/SDA
upstream pair fans out to four downstream pairs, or
channels. Any individual SCn/SDn channel or
combination of channels can be selected, determined
by the contents of the programmable control register.
An active-low reset (RESET) input allows the
TCA9546A to recover from a situation in which one of
the downstream I²C buses is stuck in a low state.
Pulling RESET low resets the I²C state machine and
causes all the channels to be deselected, as does the
internal power-on reset function.
The pass gates of the switches are constructed such
that the VCC pin can be used to limit the maximum
high voltage, which will be passed by the TCA9546A.
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 5.5-V tolerant.
Device Information⁽¹⁾
DEVICE NAME
PACKAGE
BODY SIZE (NOM)
TCA9546A
TSSOP (16)
SOIC (16)
5.00 mm x 4.40 mm
9.90 mm x 3.91 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
4 Simplified Application Diagram
I2C or SMBus
Master
(e.g. Processor)
SDA
V_CC
Channel 0
SD0
Slaves A0, A1...AN
SCL
SC0
RESET
Channel 1
SD1
SC1
TCA9546A
Slaves B0, B1...BN
A0
A1
A2
GND
Channel 2
SD2
SC2
Slaves C0, C1...CN
Channel 3
SD3
SC3
Slaves D0, D1...DN
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.