TCA9548A_15 Datasheet, PDF (1/35 Pages) Texas Instruments – Low-Voltage 8-Channel I2C Switch With Reset

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TCA9548A
SCPS207E – MAY 2012 – REVISED OCTOBER 2015
TCA9548A Low-Voltage 8-Channel I²C Switch With Reset
1 Features
•1 1-to-8 Bidirectional Translating Switches
• I²C Bus and SMBus Compatible
• Active-Low Reset Input
• Three Address Pins, Allowing up to Eight
TCA9548A Devices on the I²C Bus
• Channel Selection Through an 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-V Tolerant Inputs
• 0- to 400-kHz Clock Frequency
• Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
• ESD Protection Exceeds JESD 22
– ±2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– ±1000-V Charged-Device Model (C101)
2 Applications
• Servers
• Routers (Telecom Switching Equipment)
• Factory Automation
• Products With I²C Slave Address Conflicts (Such
as Multiple, Identical Temperature Sensors)
3 Description
The TCA9548A device has eight bidirectional
translating switches that can be controlled through
the I²C bus. The SCL/SDA upstream pair fans out to
eight 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.
The system master can reset the TCA9548A in the
event of a time-out or other improper operation by
asserting a low in the RESET input. Similarly, the
power-on reset deselects all channels and initializes
the I²C/SMBus state machine. Asserting RESET
causes the same reset and initialization to occur
without powering down the part.
The pass gates of the switches are constructed so
that the VCC pin can be used to limit the maximum
high voltage, which is passed by the TCA9548A.
Limiting the maximum high voltage allows the use of
different bus voltages on each pair, so that 1.8-V or
2.5-V or 3.3-V parts can communicate with 5-V parts,
without any additional protection. External pullup
resistors pull the bus up to the desired voltage level
for each channel. All I/O pins are 5-V tolerant.
Device Information⁽¹⁾
PART NUMBER PACKAGE
BODY SIZE (NOM)
TCA9548A
TSSOP (24)
VQFN (24)
7.80 mm × 4.40 mm
4.00 mm × 4.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Application Diagram
I2C or SMBus
Master
(processor)
SDA
SCL
VCC
RESET
Channel 0
SD0
SC0
Slaves A0, A1...AN
Channel 1
SD1
SC1
Slaves B0, B1...BN
TCA9548A
SD2
SC2
A0
A1
A2
GND
SD7
SC7
Channel 2
Channel 7
Slaves C0, C1...CN
Slaves H0, H1...HN
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.